nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "parser.h"
  27 #include "diagnostic.h"
  28 #include "format_check.h"
  29 #include "lexer.h"
  30 #include "symbol_t.h"
  31 #include "token_t.h"
  32 #include "types.h"
  33 #include "type_t.h"
  34 #include "type_hash.h"
  35 #include "ast_t.h"
  36 #include "entity_t.h"
  37 #include "attribute_t.h"
  38 #include "lang_features.h"
  39 #include "walk_statements.h"
  40 #include "warning.h"
  41 #include "printer.h"
  42 #include "adt/bitfiddle.h"
  43 #include "adt/error.h"
  44 #include "adt/array.h"
  45
  46 //#define PRINT_TOKENS
  47 #define MAX_LOOKAHEAD 1
  48
  49 typedef struct {
  50         entity_t           *old_entity;
  51         symbol_t           *symbol;
  52         entity_namespace_t  namespc;
  53 } stack_entry_t;
  54
  55 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  56 struct declaration_specifiers_t {
  57         source_position_t  source_position;
  58         storage_class_t    storage_class;
  59         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  60         bool               is_inline    : 1;
  61         bool               thread_local : 1;  /**< GCC __thread */
  62         attribute_t       *attributes;        /**< list of attributes */
  63         type_t            *type;
  64 };
  65
  66 /**
  67  * An environment for parsing initializers (and compound literals).
  68  */
  69 typedef struct parse_initializer_env_t {
  70         type_t     *type;   /**< the type of the initializer. In case of an
  71                                  array type with unspecified size this gets
  72                                  adjusted to the actual size. */
  73         entity_t   *entity; /**< the variable that is initialized if any */
  74         bool        must_be_constant;
  75 } parse_initializer_env_t;
  76
  77 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  78
  79 /** The current token. */
  80 static token_t              token;
  81 /** The lookahead ring-buffer. */
  82 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  83 /** Position of the next token in the lookahead buffer. */
  84 static size_t               lookahead_bufpos;
  85 static stack_entry_t       *environment_stack = NULL;
  86 static stack_entry_t       *label_stack       = NULL;
  87 static scope_t             *file_scope        = NULL;
  88 static scope_t             *current_scope     = NULL;
  89 /** Point to the current function declaration if inside a function. */
  90 static function_t          *current_function  = NULL;
  91 static entity_t            *current_entity    = NULL;
  92 static entity_t            *current_init_decl = NULL;
  93 static switch_statement_t  *current_switch    = NULL;
  94 static statement_t         *current_loop      = NULL;
  95 static statement_t         *current_parent    = NULL;
  96 static ms_try_statement_t  *current_try       = NULL;
  97 static linkage_kind_t       current_linkage   = LINKAGE_INVALID;
  98 static goto_statement_t    *goto_first        = NULL;
  99 static goto_statement_t   **goto_anchor       = NULL;
 100 static label_statement_t   *label_first       = NULL;
 101 static label_statement_t  **label_anchor      = NULL;
 102 /** current translation unit. */
 103 static translation_unit_t  *unit              = NULL;
 104 /** true if we are in a type property context (evaluation only for type) */
 105 static bool                 in_type_prop      = false;
 106 /** true if we are in an __extension__ context. */
 107 static bool                 in_gcc_extension  = false;
 108 static struct obstack       temp_obst;
 109 static entity_t            *anonymous_entity;
 110 static declaration_t      **incomplete_arrays;
 111
 112
 113 #define PUSH_PARENT(stmt)                          \
 114         statement_t *const prev_parent = current_parent; \
 115         ((void)(current_parent = (stmt)))
 116 #define POP_PARENT ((void)(current_parent = prev_parent))
 117
 118 /** special symbol used for anonymous entities. */
 119 static symbol_t *sym_anonymous = NULL;
 120
 121 /** The token anchor set */
 122 static unsigned char token_anchor_set[T_LAST_TOKEN];
 123
 124 /** The current source position. */
 125 #define HERE (&token.source_position)
 126
 127 /** true if we are in GCC mode. */
 128 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 129
 130 static statement_t *parse_compound_statement(bool inside_expression_statement);
 131 static statement_t *parse_statement(void);
 132
 133 static expression_t *parse_subexpression(precedence_t);
 134 static expression_t *parse_expression(void);
 135 static type_t       *parse_typename(void);
 136 static void          parse_externals(void);
 137 static void          parse_external(void);
 138
 139 static void parse_compound_type_entries(compound_t *compound_declaration);
 140
 141 static void check_call_argument(type_t          *expected_type,
 142                                                                 call_argument_t *argument, unsigned pos);
 143
 144 typedef enum declarator_flags_t {
 145         DECL_FLAGS_NONE             = 0,
 146         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 147         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 148         DECL_IS_PARAMETER           = 1U << 2
 149 } declarator_flags_t;
 150
 151 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 152                                   declarator_flags_t flags);
 153
 154 static void semantic_comparison(binary_expression_t *expression);
 155
 156 #define STORAGE_CLASSES       \
 157         STORAGE_CLASSES_NO_EXTERN \
 158         case T_extern:
 159
 160 #define STORAGE_CLASSES_NO_EXTERN \
 161         case T_typedef:         \
 162         case T_static:          \
 163         case T_auto:            \
 164         case T_register:        \
 165         case T___thread:
 166
 167 #define TYPE_QUALIFIERS     \
 168         case T_const:           \
 169         case T_restrict:        \
 170         case T_volatile:        \
 171         case T_inline:          \
 172         case T__forceinline:    \
 173         case T___attribute__:
 174
 175 #define COMPLEX_SPECIFIERS  \
 176         case T__Complex:
 177 #define IMAGINARY_SPECIFIERS \
 178         case T__Imaginary:
 179
 180 #define TYPE_SPECIFIERS       \
 181         case T__Bool:             \
 182         case T___builtin_va_list: \
 183         case T___typeof__:        \
 184         case T__declspec:         \
 185         case T_bool:              \
 186         case T_char:              \
 187         case T_double:            \
 188         case T_enum:              \
 189         case T_float:             \
 190         case T_int:               \
 191         case T_long:              \
 192         case T_short:             \
 193         case T_signed:            \
 194         case T_struct:            \
 195         case T_union:             \
 196         case T_unsigned:          \
 197         case T_void:              \
 198         case T_wchar_t:           \
 199         case T__int8:             \
 200         case T__int16:            \
 201         case T__int32:            \
 202         case T__int64:            \
 203         case T__int128:           \
 204         COMPLEX_SPECIFIERS        \
 205         IMAGINARY_SPECIFIERS
 206
 207 #define DECLARATION_START   \
 208         STORAGE_CLASSES         \
 209         TYPE_QUALIFIERS         \
 210         TYPE_SPECIFIERS
 211
 212 #define DECLARATION_START_NO_EXTERN \
 213         STORAGE_CLASSES_NO_EXTERN       \
 214         TYPE_QUALIFIERS                 \
 215         TYPE_SPECIFIERS
 216
 217 #define TYPENAME_START      \
 218         TYPE_QUALIFIERS         \
 219         TYPE_SPECIFIERS
 220
 221 #define EXPRESSION_START              \
 222         case '!':                         \
 223         case '&':                         \
 224         case '(':                         \
 225         case '*':                         \
 226         case '+':                         \
 227         case '-':                         \
 228         case '~':                         \
 229         case T_ANDAND:                    \
 230         case T_CHARACTER_CONSTANT:        \
 231         case T_FLOATINGPOINT:             \
 232         case T_FLOATINGPOINT_HEXADECIMAL: \
 233         case T_INTEGER:                   \
 234         case T_INTEGER_HEXADECIMAL:       \
 235         case T_INTEGER_OCTAL:             \
 236         case T_MINUSMINUS:                \
 237         case T_PLUSPLUS:                  \
 238         case T_STRING_LITERAL:            \
 239         case T_WIDE_CHARACTER_CONSTANT:   \
 240         case T_WIDE_STRING_LITERAL:       \
 241         case T___FUNCDNAME__:             \
 242         case T___FUNCSIG__:               \
 243         case T___FUNCTION__:              \
 244         case T___PRETTY_FUNCTION__:       \
 245         case T___alignof__:               \
 246         case T___builtin_classify_type:   \
 247         case T___builtin_constant_p:      \
 248         case T___builtin_isgreater:       \
 249         case T___builtin_isgreaterequal:  \
 250         case T___builtin_isless:          \
 251         case T___builtin_islessequal:     \
 252         case T___builtin_islessgreater:   \
 253         case T___builtin_isunordered:     \
 254         case T___builtin_offsetof:        \
 255         case T___builtin_va_arg:          \
 256         case T___builtin_va_copy:         \
 257         case T___builtin_va_start:        \
 258         case T___func__:                  \
 259         case T___noop:                    \
 260         case T__assume:                   \
 261         case T_delete:                    \
 262         case T_false:                     \
 263         case T_sizeof:                    \
 264         case T_throw:                     \
 265         case T_true:
 266
 267 /**
 268  * Returns the size of a statement node.
 269  *
 270  * @param kind  the statement kind
 271  */
 272 static size_t get_statement_struct_size(statement_kind_t kind)
 273 {
 274         static const size_t sizes[] = {
 275                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 276                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 277                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 278                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 279                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 280                 [STATEMENT_IF]          = sizeof(if_statement_t),
 281                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 282                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 283                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 284                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 285                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 286                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 287                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 288                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 289                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 290                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 291                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 292                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 293                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 294         };
 295         assert(kind < lengthof(sizes));
 296         assert(sizes[kind] != 0);
 297         return sizes[kind];
 298 }
 299
 300 /**
 301  * Returns the size of an expression node.
 302  *
 303  * @param kind  the expression kind
 304  */
 305 static size_t get_expression_struct_size(expression_kind_t kind)
 306 {
 307         static const size_t sizes[] = {
 308                 [EXPR_INVALID]                    = sizeof(expression_base_t),
 309                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 310                 [EXPR_REFERENCE_ENUM_VALUE]       = sizeof(reference_expression_t),
 311                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 312                 [EXPR_LITERAL_INTEGER_OCTAL]      = sizeof(literal_expression_t),
 313                 [EXPR_LITERAL_INTEGER_HEXADECIMAL]= sizeof(literal_expression_t),
 314                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 315                 [EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL] = sizeof(literal_expression_t),
 316                 [EXPR_LITERAL_CHARACTER]          = sizeof(literal_expression_t),
 317                 [EXPR_LITERAL_WIDE_CHARACTER]     = sizeof(literal_expression_t),
 318                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 319                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(string_literal_expression_t),
 320                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 321                 [EXPR_CALL]                       = sizeof(call_expression_t),
 322                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 323                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 324                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 325                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 326                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 327                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 328                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 329                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 330                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 331                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 332                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 333                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 334                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 335                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 336                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 337                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 338                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 339         };
 340         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 341                 return sizes[EXPR_UNARY_FIRST];
 342         }
 343         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 344                 return sizes[EXPR_BINARY_FIRST];
 345         }
 346         assert(kind < lengthof(sizes));
 347         assert(sizes[kind] != 0);
 348         return sizes[kind];
 349 }
 350
 351 /**
 352  * Allocate a statement node of given kind and initialize all
 353  * fields with zero. Sets its source position to the position
 354  * of the current token.
 355  */
 356 static statement_t *allocate_statement_zero(statement_kind_t kind)
 357 {
 358         size_t       size = get_statement_struct_size(kind);
 359         statement_t *res  = allocate_ast_zero(size);
 360
 361         res->base.kind            = kind;
 362         res->base.parent          = current_parent;
 363         res->base.source_position = token.source_position;
 364         return res;
 365 }
 366
 367 /**
 368  * Allocate an expression node of given kind and initialize all
 369  * fields with zero.
 370  *
 371  * @param kind  the kind of the expression to allocate
 372  */
 373 static expression_t *allocate_expression_zero(expression_kind_t kind)
 374 {
 375         size_t        size = get_expression_struct_size(kind);
 376         expression_t *res  = allocate_ast_zero(size);
 377
 378         res->base.kind            = kind;
 379         res->base.type            = type_error_type;
 380         res->base.source_position = token.source_position;
 381         return res;
 382 }
 383
 384 /**
 385  * Creates a new invalid expression at the source position
 386  * of the current token.
 387  */
 388 static expression_t *create_invalid_expression(void)
 389 {
 390         return allocate_expression_zero(EXPR_INVALID);
 391 }
 392
 393 /**
 394  * Creates a new invalid statement.
 395  */
 396 static statement_t *create_invalid_statement(void)
 397 {
 398         return allocate_statement_zero(STATEMENT_INVALID);
 399 }
 400
 401 /**
 402  * Allocate a new empty statement.
 403  */
 404 static statement_t *create_empty_statement(void)
 405 {
 406         return allocate_statement_zero(STATEMENT_EMPTY);
 407 }
 408
 409 static function_parameter_t *allocate_parameter(type_t *const type)
 410 {
 411         function_parameter_t *const param
 412                 = obstack_alloc(type_obst, sizeof(*param));
 413         memset(param, 0, sizeof(*param));
 414         param->type = type;
 415         return param;
 416 }
 417
 418 /**
 419  * Returns the size of an initializer node.
 420  *
 421  * @param kind  the initializer kind
 422  */
 423 static size_t get_initializer_size(initializer_kind_t kind)
 424 {
 425         static const size_t sizes[] = {
 426                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 427                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 428                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 429                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 430                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 431         };
 432         assert(kind < lengthof(sizes));
 433         assert(sizes[kind] != 0);
 434         return sizes[kind];
 435 }
 436
 437 /**
 438  * Allocate an initializer node of given kind and initialize all
 439  * fields with zero.
 440  */
 441 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 442 {
 443         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 444         result->kind          = kind;
 445
 446         return result;
 447 }
 448
 449 /**
 450  * Returns the index of the top element of the environment stack.
 451  */
 452 static size_t environment_top(void)
 453 {
 454         return ARR_LEN(environment_stack);
 455 }
 456
 457 /**
 458  * Returns the index of the top element of the global label stack.
 459  */
 460 static size_t label_top(void)
 461 {
 462         return ARR_LEN(label_stack);
 463 }
 464
 465 /**
 466  * Return the next token.
 467  */
 468 static inline void next_token(void)
 469 {
 470         token                              = lookahead_buffer[lookahead_bufpos];
 471         lookahead_buffer[lookahead_bufpos] = lexer_token;
 472         lexer_next_token();
 473
 474         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 475
 476 #ifdef PRINT_TOKENS
 477         print_token(stderr, &token);
 478         fprintf(stderr, "\n");
 479 #endif
 480 }
 481
 482 static inline bool next_if(int const type)
 483 {
 484         if (token.type == type) {
 485                 next_token();
 486                 return true;
 487         } else {
 488                 return false;
 489         }
 490 }
 491
 492 /**
 493  * Return the next token with a given lookahead.
 494  */
 495 static inline const token_t *look_ahead(size_t num)
 496 {
 497         assert(0 < num && num <= MAX_LOOKAHEAD);
 498         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 499         return &lookahead_buffer[pos];
 500 }
 501
 502 /**
 503  * Adds a token type to the token type anchor set (a multi-set).
 504  */
 505 static void add_anchor_token(int token_type)
 506 {
 507         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 508         ++token_anchor_set[token_type];
 509 }
 510
 511 /**
 512  * Set the number of tokens types of the given type
 513  * to zero and return the old count.
 514  */
 515 static int save_and_reset_anchor_state(int token_type)
 516 {
 517         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 518         int count = token_anchor_set[token_type];
 519         token_anchor_set[token_type] = 0;
 520         return count;
 521 }
 522
 523 /**
 524  * Restore the number of token types to the given count.
 525  */
 526 static void restore_anchor_state(int token_type, int count)
 527 {
 528         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 529         token_anchor_set[token_type] = count;
 530 }
 531
 532 /**
 533  * Remove a token type from the token type anchor set (a multi-set).
 534  */
 535 static void rem_anchor_token(int token_type)
 536 {
 537         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 538         assert(token_anchor_set[token_type] != 0);
 539         --token_anchor_set[token_type];
 540 }
 541
 542 /**
 543  * Return true if the token type of the current token is
 544  * in the anchor set.
 545  */
 546 static bool at_anchor(void)
 547 {
 548         if (token.type < 0)
 549                 return false;
 550         return token_anchor_set[token.type];
 551 }
 552
 553 /**
 554  * Eat tokens until a matching token type is found.
 555  */
 556 static void eat_until_matching_token(int type)
 557 {
 558         int end_token;
 559         switch (type) {
 560                 case '(': end_token = ')';  break;
 561                 case '{': end_token = '}';  break;
 562                 case '[': end_token = ']';  break;
 563                 default:  end_token = type; break;
 564         }
 565
 566         unsigned parenthesis_count = 0;
 567         unsigned brace_count       = 0;
 568         unsigned bracket_count     = 0;
 569         while (token.type        != end_token ||
 570                parenthesis_count != 0         ||
 571                brace_count       != 0         ||
 572                bracket_count     != 0) {
 573                 switch (token.type) {
 574                 case T_EOF: return;
 575                 case '(': ++parenthesis_count; break;
 576                 case '{': ++brace_count;       break;
 577                 case '[': ++bracket_count;     break;
 578
 579                 case ')':
 580                         if (parenthesis_count > 0)
 581                                 --parenthesis_count;
 582                         goto check_stop;
 583
 584                 case '}':
 585                         if (brace_count > 0)
 586                                 --brace_count;
 587                         goto check_stop;
 588
 589                 case ']':
 590                         if (bracket_count > 0)
 591                                 --bracket_count;
 592 check_stop:
 593                         if (token.type        == end_token &&
 594                             parenthesis_count == 0         &&
 595                             brace_count       == 0         &&
 596                             bracket_count     == 0)
 597                                 return;
 598                         break;
 599
 600                 default:
 601                         break;
 602                 }
 603                 next_token();
 604         }
 605 }
 606
 607 /**
 608  * Eat input tokens until an anchor is found.
 609  */
 610 static void eat_until_anchor(void)
 611 {
 612         while (token_anchor_set[token.type] == 0) {
 613                 if (token.type == '(' || token.type == '{' || token.type == '[')
 614                         eat_until_matching_token(token.type);
 615                 next_token();
 616         }
 617 }
 618
 619 /**
 620  * Eat a whole block from input tokens.
 621  */
 622 static void eat_block(void)
 623 {
 624         eat_until_matching_token('{');
 625         next_if('}');
 626 }
 627
 628 #define eat(token_type) (assert(token.type == (token_type)), next_token())
 629
 630 /**
 631  * Report a parse error because an expected token was not found.
 632  */
 633 static
 634 #if defined __GNUC__ && __GNUC__ >= 4
 635 __attribute__((sentinel))
 636 #endif
 637 void parse_error_expected(const char *message, ...)
 638 {
 639         if (message != NULL) {
 640                 errorf(HERE, "%s", message);
 641         }
 642         va_list ap;
 643         va_start(ap, message);
 644         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 645         va_end(ap);
 646 }
 647
 648 /**
 649  * Report an incompatible type.
 650  */
 651 static void type_error_incompatible(const char *msg,
 652                 const source_position_t *source_position, type_t *type1, type_t *type2)
 653 {
 654         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 655                msg, type1, type2);
 656 }
 657
 658 /**
 659  * Expect the current token is the expected token.
 660  * If not, generate an error, eat the current statement,
 661  * and goto the error_label label.
 662  */
 663 #define expect(expected, error_label)                     \
 664         do {                                                  \
 665                 if (UNLIKELY(token.type != (expected))) {         \
 666                         parse_error_expected(NULL, (expected), NULL); \
 667                         add_anchor_token(expected);                   \
 668                         eat_until_anchor();                           \
 669                         next_if((expected));                          \
 670                         rem_anchor_token(expected);                   \
 671                         goto error_label;                             \
 672                 }                                                 \
 673                 next_token();                                     \
 674         } while (0)
 675
 676 /**
 677  * Push a given scope on the scope stack and make it the
 678  * current scope
 679  */
 680 static scope_t *scope_push(scope_t *new_scope)
 681 {
 682         if (current_scope != NULL) {
 683                 new_scope->depth = current_scope->depth + 1;
 684         }
 685
 686         scope_t *old_scope = current_scope;
 687         current_scope      = new_scope;
 688         return old_scope;
 689 }
 690
 691 /**
 692  * Pop the current scope from the scope stack.
 693  */
 694 static void scope_pop(scope_t *old_scope)
 695 {
 696         current_scope = old_scope;
 697 }
 698
 699 /**
 700  * Search an entity by its symbol in a given namespace.
 701  */
 702 static entity_t *get_entity(const symbol_t *const symbol,
 703                             namespace_tag_t namespc)
 704 {
 705         assert(namespc != NAMESPACE_INVALID);
 706         entity_t *entity = symbol->entity;
 707         for (; entity != NULL; entity = entity->base.symbol_next) {
 708                 if (entity->base.namespc == namespc)
 709                         return entity;
 710         }
 711
 712         return NULL;
 713 }
 714
 715 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 716  * possible. */
 717 static entity_t *get_tag(symbol_t const *const symbol,
 718                          entity_kind_tag_t const kind)
 719 {
 720         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 721         if (entity != NULL && entity->kind != kind) {
 722                 errorf(HERE,
 723                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 724                                 symbol, &entity->base.source_position);
 725                 entity = NULL;
 726         }
 727         return entity;
 728 }
 729
 730 /**
 731  * pushs an entity on the environment stack and links the corresponding symbol
 732  * it.
 733  */
 734 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 735 {
 736         symbol_t           *symbol  = entity->base.symbol;
 737         entity_namespace_t  namespc = entity->base.namespc;
 738         assert(namespc != NAMESPACE_INVALID);
 739
 740         /* replace/add entity into entity list of the symbol */
 741         entity_t **anchor;
 742         entity_t  *iter;
 743         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 744                 iter = *anchor;
 745                 if (iter == NULL)
 746                         break;
 747
 748                 /* replace an entry? */
 749                 if (iter->base.namespc == namespc) {
 750                         entity->base.symbol_next = iter->base.symbol_next;
 751                         break;
 752                 }
 753         }
 754         *anchor = entity;
 755
 756         /* remember old declaration */
 757         stack_entry_t entry;
 758         entry.symbol     = symbol;
 759         entry.old_entity = iter;
 760         entry.namespc    = namespc;
 761         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 762 }
 763
 764 /**
 765  * Push an entity on the environment stack.
 766  */
 767 static void environment_push(entity_t *entity)
 768 {
 769         assert(entity->base.source_position.input_name != NULL);
 770         assert(entity->base.parent_scope != NULL);
 771         stack_push(&environment_stack, entity);
 772 }
 773
 774 /**
 775  * Push a declaration on the global label stack.
 776  *
 777  * @param declaration  the declaration
 778  */
 779 static void label_push(entity_t *label)
 780 {
 781         /* we abuse the parameters scope as parent for the labels */
 782         label->base.parent_scope = &current_function->parameters;
 783         stack_push(&label_stack, label);
 784 }
 785
 786 /**
 787  * pops symbols from the environment stack until @p new_top is the top element
 788  */
 789 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 790 {
 791         stack_entry_t *stack = *stack_ptr;
 792         size_t         top   = ARR_LEN(stack);
 793         size_t         i;
 794
 795         assert(new_top <= top);
 796         if (new_top == top)
 797                 return;
 798
 799         for (i = top; i > new_top; --i) {
 800                 stack_entry_t *entry = &stack[i - 1];
 801
 802                 entity_t           *old_entity = entry->old_entity;
 803                 symbol_t           *symbol     = entry->symbol;
 804                 entity_namespace_t  namespc    = entry->namespc;
 805
 806                 /* replace with old_entity/remove */
 807                 entity_t **anchor;
 808                 entity_t  *iter;
 809                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 810                         iter = *anchor;
 811                         assert(iter != NULL);
 812                         /* replace an entry? */
 813                         if (iter->base.namespc == namespc)
 814                                 break;
 815                 }
 816
 817                 /* restore definition from outer scopes (if there was one) */
 818                 if (old_entity != NULL) {
 819                         old_entity->base.symbol_next = iter->base.symbol_next;
 820                         *anchor                      = old_entity;
 821                 } else {
 822                         /* remove entry from list */
 823                         *anchor = iter->base.symbol_next;
 824                 }
 825         }
 826
 827         ARR_SHRINKLEN(*stack_ptr, new_top);
 828 }
 829
 830 /**
 831  * Pop all entries from the environment stack until the new_top
 832  * is reached.
 833  *
 834  * @param new_top  the new stack top
 835  */
 836 static void environment_pop_to(size_t new_top)
 837 {
 838         stack_pop_to(&environment_stack, new_top);
 839 }
 840
 841 /**
 842  * Pop all entries from the global label stack until the new_top
 843  * is reached.
 844  *
 845  * @param new_top  the new stack top
 846  */
 847 static void label_pop_to(size_t new_top)
 848 {
 849         stack_pop_to(&label_stack, new_top);
 850 }
 851
 852 static int get_akind_rank(atomic_type_kind_t akind)
 853 {
 854         return (int) akind;
 855 }
 856
 857 /**
 858  * Return the type rank for an atomic type.
 859  */
 860 static int get_rank(const type_t *type)
 861 {
 862         assert(!is_typeref(type));
 863         if (type->kind == TYPE_ENUM)
 864                 return get_akind_rank(type->enumt.akind);
 865
 866         assert(type->kind == TYPE_ATOMIC);
 867         return get_akind_rank(type->atomic.akind);
 868 }
 869
 870 /**
 871  * §6.3.1.1:2  Do integer promotion for a given type.
 872  *
 873  * @param type  the type to promote
 874  * @return the promoted type
 875  */
 876 static type_t *promote_integer(type_t *type)
 877 {
 878         if (type->kind == TYPE_BITFIELD)
 879                 type = type->bitfield.base_type;
 880
 881         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 882                 type = type_int;
 883
 884         return type;
 885 }
 886
 887 /**
 888  * Create a cast expression.
 889  *
 890  * @param expression  the expression to cast
 891  * @param dest_type   the destination type
 892  */
 893 static expression_t *create_cast_expression(expression_t *expression,
 894                                             type_t *dest_type)
 895 {
 896         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 897
 898         cast->unary.value = expression;
 899         cast->base.type   = dest_type;
 900
 901         return cast;
 902 }
 903
 904 /**
 905  * Check if a given expression represents a null pointer constant.
 906  *
 907  * @param expression  the expression to check
 908  */
 909 static bool is_null_pointer_constant(const expression_t *expression)
 910 {
 911         /* skip void* cast */
 912         if (expression->kind == EXPR_UNARY_CAST ||
 913                         expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 914                 type_t *const type = skip_typeref(expression->base.type);
 915                 if (types_compatible(type, type_void_ptr))
 916                         expression = expression->unary.value;
 917         }
 918
 919         type_t *const type = skip_typeref(expression->base.type);
 920         if (!is_type_integer(type))
 921                 return false;
 922         switch (is_constant_expression(expression)) {
 923                 case EXPR_CLASS_ERROR:    return true;
 924                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 925                 default:                  return false;
 926         }
 927 }
 928
 929 /**
 930  * Create an implicit cast expression.
 931  *
 932  * @param expression  the expression to cast
 933  * @param dest_type   the destination type
 934  */
 935 static expression_t *create_implicit_cast(expression_t *expression,
 936                                           type_t *dest_type)
 937 {
 938         type_t *const source_type = expression->base.type;
 939
 940         if (source_type == dest_type)
 941                 return expression;
 942
 943         return create_cast_expression(expression, dest_type);
 944 }
 945
 946 typedef enum assign_error_t {
 947         ASSIGN_SUCCESS,
 948         ASSIGN_ERROR_INCOMPATIBLE,
 949         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 950         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 951         ASSIGN_WARNING_POINTER_FROM_INT,
 952         ASSIGN_WARNING_INT_FROM_POINTER
 953 } assign_error_t;
 954
 955 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
 956                                 const expression_t *const right,
 957                                 const char *context,
 958                                 const source_position_t *source_position)
 959 {
 960         type_t *const orig_type_right = right->base.type;
 961         type_t *const type_left       = skip_typeref(orig_type_left);
 962         type_t *const type_right      = skip_typeref(orig_type_right);
 963
 964         switch (error) {
 965         case ASSIGN_SUCCESS:
 966                 return;
 967         case ASSIGN_ERROR_INCOMPATIBLE:
 968                 errorf(source_position,
 969                        "destination type '%T' in %s is incompatible with type '%T'",
 970                        orig_type_left, context, orig_type_right);
 971                 return;
 972
 973         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 974                 if (warning.other) {
 975                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 976                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 977
 978                         /* the left type has all qualifiers from the right type */
 979                         unsigned missing_qualifiers
 980                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 981                         warningf(source_position,
 982                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
 983                                         orig_type_left, context, orig_type_right, missing_qualifiers);
 984                 }
 985                 return;
 986         }
 987
 988         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 989                 if (warning.other) {
 990                         warningf(source_position,
 991                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
 992                                         orig_type_left, context, right, orig_type_right);
 993                 }
 994                 return;
 995
 996         case ASSIGN_WARNING_POINTER_FROM_INT:
 997                 if (warning.other) {
 998                         warningf(source_position,
 999                                         "%s makes pointer '%T' from integer '%T' without a cast",
1000                                         context, orig_type_left, orig_type_right);
1001                 }
1002                 return;
1003
1004         case ASSIGN_WARNING_INT_FROM_POINTER:
1005                 if (warning.other) {
1006                         warningf(source_position,
1007                                         "%s makes integer '%T' from pointer '%T' without a cast",
1008                                         context, orig_type_left, orig_type_right);
1009                 }
1010                 return;
1011
1012         default:
1013                 panic("invalid error value");
1014         }
1015 }
1016
1017 /** Implements the rules from §6.5.16.1 */
1018 static assign_error_t semantic_assign(type_t *orig_type_left,
1019                                       const expression_t *const right)
1020 {
1021         type_t *const orig_type_right = right->base.type;
1022         type_t *const type_left       = skip_typeref(orig_type_left);
1023         type_t *const type_right      = skip_typeref(orig_type_right);
1024
1025         if (is_type_pointer(type_left)) {
1026                 if (is_null_pointer_constant(right)) {
1027                         return ASSIGN_SUCCESS;
1028                 } else if (is_type_pointer(type_right)) {
1029                         type_t *points_to_left
1030                                 = skip_typeref(type_left->pointer.points_to);
1031                         type_t *points_to_right
1032                                 = skip_typeref(type_right->pointer.points_to);
1033                         assign_error_t res = ASSIGN_SUCCESS;
1034
1035                         /* the left type has all qualifiers from the right type */
1036                         unsigned missing_qualifiers
1037                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1038                         if (missing_qualifiers != 0) {
1039                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1040                         }
1041
1042                         points_to_left  = get_unqualified_type(points_to_left);
1043                         points_to_right = get_unqualified_type(points_to_right);
1044
1045                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1046                                 return res;
1047
1048                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1049                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1050                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1051                         }
1052
1053                         if (!types_compatible(points_to_left, points_to_right)) {
1054                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1055                         }
1056
1057                         return res;
1058                 } else if (is_type_integer(type_right)) {
1059                         return ASSIGN_WARNING_POINTER_FROM_INT;
1060                 }
1061         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1062                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1063                                 && is_type_pointer(type_right))) {
1064                 return ASSIGN_SUCCESS;
1065         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1066                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1067                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1068                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1069                         return ASSIGN_SUCCESS;
1070                 }
1071         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1072                 return ASSIGN_WARNING_INT_FROM_POINTER;
1073         }
1074
1075         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1076                 return ASSIGN_SUCCESS;
1077
1078         return ASSIGN_ERROR_INCOMPATIBLE;
1079 }
1080
1081 static expression_t *parse_constant_expression(void)
1082 {
1083         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1084
1085         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1086                 errorf(&result->base.source_position,
1087                        "expression '%E' is not constant", result);
1088         }
1089
1090         return result;
1091 }
1092
1093 static expression_t *parse_assignment_expression(void)
1094 {
1095         return parse_subexpression(PREC_ASSIGNMENT);
1096 }
1097
1098 static void warn_string_concat(const source_position_t *pos)
1099 {
1100         if (warning.traditional) {
1101                 warningf(pos, "traditional C rejects string constant concatenation");
1102         }
1103 }
1104
1105 static string_t parse_string_literals(void)
1106 {
1107         assert(token.type == T_STRING_LITERAL);
1108         string_t result = token.literal;
1109
1110         next_token();
1111
1112         while (token.type == T_STRING_LITERAL) {
1113                 warn_string_concat(&token.source_position);
1114                 result = concat_strings(&result, &token.literal);
1115                 next_token();
1116         }
1117
1118         return result;
1119 }
1120
1121 /**
1122  * compare two string, ignoring double underscores on the second.
1123  */
1124 static int strcmp_underscore(const char *s1, const char *s2)
1125 {
1126         if (s2[0] == '_' && s2[1] == '_') {
1127                 size_t len2 = strlen(s2);
1128                 size_t len1 = strlen(s1);
1129                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1130                         return strncmp(s1, s2+2, len2-4);
1131                 }
1132         }
1133
1134         return strcmp(s1, s2);
1135 }
1136
1137 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1138 {
1139         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1140         attribute->kind        = kind;
1141         return attribute;
1142 }
1143
1144 /**
1145  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1146  *
1147  *  attribute:
1148  *    __attribute__ ( ( attribute-list ) )
1149  *
1150  *  attribute-list:
1151  *    attrib
1152  *    attribute_list , attrib
1153  *
1154  *  attrib:
1155  *    empty
1156  *    any-word
1157  *    any-word ( identifier )
1158  *    any-word ( identifier , nonempty-expr-list )
1159  *    any-word ( expr-list )
1160  *
1161  *  where the "identifier" must not be declared as a type, and
1162  *  "any-word" may be any identifier (including one declared as a
1163  *  type), a reserved word storage class specifier, type specifier or
1164  *  type qualifier.  ??? This still leaves out most reserved keywords
1165  *  (following the old parser), shouldn't we include them, and why not
1166  *  allow identifiers declared as types to start the arguments?
1167  *
1168  *  Matze: this all looks confusing and little systematic, so we're even less
1169  *  strict and parse any list of things which are identifiers or
1170  *  (assignment-)expressions.
1171  */
1172 static attribute_argument_t *parse_attribute_arguments(void)
1173 {
1174         attribute_argument_t  *first  = NULL;
1175         attribute_argument_t **anchor = &first;
1176         if (token.type != ')') do {
1177                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1178
1179                 /* is it an identifier */
1180                 if (token.type == T_IDENTIFIER
1181                                 && (look_ahead(1)->type == ',' || look_ahead(1)->type == ')')) {
1182                         symbol_t *symbol   = token.symbol;
1183                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1184                         argument->v.symbol = symbol;
1185                         next_token();
1186                 } else {
1187                         /* must be an expression */
1188                         expression_t *expression = parse_assignment_expression();
1189
1190                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1191                         argument->v.expression = expression;
1192                 }
1193
1194                 /* append argument */
1195                 *anchor = argument;
1196                 anchor  = &argument->next;
1197         } while (next_if(','));
1198         expect(')', end_error);
1199
1200         return first;
1201
1202 end_error:
1203         /* TODO... */
1204         return first;
1205 }
1206
1207 static attribute_t *parse_attribute_asm(void)
1208 {
1209         eat(T_asm);
1210
1211         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1212
1213         expect('(', end_error);
1214         attribute->a.arguments = parse_attribute_arguments();
1215         return attribute;
1216
1217 end_error:
1218         return NULL;
1219 }
1220
1221 static symbol_t *get_symbol_from_token(void)
1222 {
1223         switch(token.type) {
1224         case T_IDENTIFIER:
1225                 return token.symbol;
1226         case T_auto:
1227         case T_char:
1228         case T_double:
1229         case T_enum:
1230         case T_extern:
1231         case T_float:
1232         case T_int:
1233         case T_long:
1234         case T_register:
1235         case T_short:
1236         case T_static:
1237         case T_struct:
1238         case T_union:
1239         case T_unsigned:
1240         case T_void:
1241         case T_bool:
1242         case T__Bool:
1243         case T_class:
1244         case T_explicit:
1245         case T_export:
1246         case T_wchar_t:
1247         case T_const:
1248         case T_signed:
1249         case T___real__:
1250         case T___imag__:
1251         case T_restrict:
1252         case T_volatile:
1253         case T_inline:
1254                 /* maybe we need more tokens ... add them on demand */
1255                 return get_token_symbol(&token);
1256         default:
1257                 return NULL;
1258         }
1259 }
1260
1261 static attribute_t *parse_attribute_gnu_single(void)
1262 {
1263         /* parse "any-word" */
1264         symbol_t *symbol = get_symbol_from_token();
1265         if (symbol == NULL) {
1266                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1267                 return NULL;
1268         }
1269
1270         const char *name = symbol->string;
1271         next_token();
1272
1273         attribute_kind_t kind;
1274         for (kind = ATTRIBUTE_GNU_FIRST; kind <= ATTRIBUTE_GNU_LAST; ++kind) {
1275                 const char *attribute_name = get_attribute_name(kind);
1276                 if (attribute_name != NULL
1277                                 && strcmp_underscore(attribute_name, name) == 0)
1278                         break;
1279         }
1280
1281         if (kind >= ATTRIBUTE_GNU_LAST) {
1282                 if (warning.attribute) {
1283                         warningf(HERE, "unknown attribute '%s' ignored", name);
1284                 }
1285                 /* TODO: we should still save the attribute in the list... */
1286                 kind = ATTRIBUTE_UNKNOWN;
1287         }
1288
1289         attribute_t *attribute = allocate_attribute_zero(kind);
1290
1291         /* parse arguments */
1292         if (next_if('('))
1293                 attribute->a.arguments = parse_attribute_arguments();
1294
1295         return attribute;
1296 }
1297
1298 static attribute_t *parse_attribute_gnu(void)
1299 {
1300         attribute_t  *first  = NULL;
1301         attribute_t **anchor = &first;
1302
1303         eat(T___attribute__);
1304         expect('(', end_error);
1305         expect('(', end_error);
1306
1307         if (token.type != ')') do {
1308                 attribute_t *attribute = parse_attribute_gnu_single();
1309                 if (attribute == NULL)
1310                         goto end_error;
1311
1312                 *anchor = attribute;
1313                 anchor  = &attribute->next;
1314         } while (next_if(','));
1315         expect(')', end_error);
1316         expect(')', end_error);
1317
1318 end_error:
1319         return first;
1320 }
1321
1322 /** Parse attributes. */
1323 static attribute_t *parse_attributes(attribute_t *first)
1324 {
1325         attribute_t **anchor = &first;
1326         for (;;) {
1327                 while (*anchor != NULL)
1328                         anchor = &(*anchor)->next;
1329
1330                 attribute_t *attribute;
1331                 switch (token.type) {
1332                 case T___attribute__:
1333                         attribute = parse_attribute_gnu();
1334                         if (attribute == NULL)
1335                                 continue;
1336                         break;
1337
1338                 case T_asm:
1339                         attribute = parse_attribute_asm();
1340                         break;
1341
1342                 case T_cdecl:
1343                         next_token();
1344                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1345                         break;
1346
1347                 case T__fastcall:
1348                         next_token();
1349                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1350                         break;
1351
1352                 case T__forceinline:
1353                         next_token();
1354                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1355                         break;
1356
1357                 case T__stdcall:
1358                         next_token();
1359                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1360                         break;
1361
1362                 case T___thiscall:
1363                         next_token();
1364                         /* TODO record modifier */
1365                         if (warning.other)
1366                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1367                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1368                         break;
1369
1370                 default:
1371                         return first;
1372                 }
1373
1374                 *anchor = attribute;
1375                 anchor  = &attribute->next;
1376         }
1377 }
1378
1379 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1380
1381 static entity_t *determine_lhs_ent(expression_t *const expr,
1382                                    entity_t *lhs_ent)
1383 {
1384         switch (expr->kind) {
1385                 case EXPR_REFERENCE: {
1386                         entity_t *const entity = expr->reference.entity;
1387                         /* we should only find variables as lvalues... */
1388                         if (entity->base.kind != ENTITY_VARIABLE
1389                                         && entity->base.kind != ENTITY_PARAMETER)
1390                                 return NULL;
1391
1392                         return entity;
1393                 }
1394
1395                 case EXPR_ARRAY_ACCESS: {
1396                         expression_t *const ref = expr->array_access.array_ref;
1397                         entity_t     *      ent = NULL;
1398                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1399                                 ent     = determine_lhs_ent(ref, lhs_ent);
1400                                 lhs_ent = ent;
1401                         } else {
1402                                 mark_vars_read(expr->select.compound, lhs_ent);
1403                         }
1404                         mark_vars_read(expr->array_access.index, lhs_ent);
1405                         return ent;
1406                 }
1407
1408                 case EXPR_SELECT: {
1409                         if (is_type_compound(skip_typeref(expr->base.type))) {
1410                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1411                         } else {
1412                                 mark_vars_read(expr->select.compound, lhs_ent);
1413                                 return NULL;
1414                         }
1415                 }
1416
1417                 case EXPR_UNARY_DEREFERENCE: {
1418                         expression_t *const val = expr->unary.value;
1419                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1420                                 /* *&x is a NOP */
1421                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1422                         } else {
1423                                 mark_vars_read(val, NULL);
1424                                 return NULL;
1425                         }
1426                 }
1427
1428                 default:
1429                         mark_vars_read(expr, NULL);
1430                         return NULL;
1431         }
1432 }
1433
1434 #define ENT_ANY ((entity_t*)-1)
1435
1436 /**
1437  * Mark declarations, which are read.  This is used to detect variables, which
1438  * are never read.
1439  * Example:
1440  * x = x + 1;
1441  *   x is not marked as "read", because it is only read to calculate its own new
1442  *   value.
1443  *
1444  * x += y; y += x;
1445  *   x and y are not detected as "not read", because multiple variables are
1446  *   involved.
1447  */
1448 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1449 {
1450         switch (expr->kind) {
1451                 case EXPR_REFERENCE: {
1452                         entity_t *const entity = expr->reference.entity;
1453                         if (entity->kind != ENTITY_VARIABLE
1454                                         && entity->kind != ENTITY_PARAMETER)
1455                                 return;
1456
1457                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1458                                 if (entity->kind == ENTITY_VARIABLE) {
1459                                         entity->variable.read = true;
1460                                 } else {
1461                                         entity->parameter.read = true;
1462                                 }
1463                         }
1464                         return;
1465                 }
1466
1467                 case EXPR_CALL:
1468                         // TODO respect pure/const
1469                         mark_vars_read(expr->call.function, NULL);
1470                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1471                                 mark_vars_read(arg->expression, NULL);
1472                         }
1473                         return;
1474
1475                 case EXPR_CONDITIONAL:
1476                         // TODO lhs_decl should depend on whether true/false have an effect
1477                         mark_vars_read(expr->conditional.condition, NULL);
1478                         if (expr->conditional.true_expression != NULL)
1479                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1480                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1481                         return;
1482
1483                 case EXPR_SELECT:
1484                         if (lhs_ent == ENT_ANY
1485                                         && !is_type_compound(skip_typeref(expr->base.type)))
1486                                 lhs_ent = NULL;
1487                         mark_vars_read(expr->select.compound, lhs_ent);
1488                         return;
1489
1490                 case EXPR_ARRAY_ACCESS: {
1491                         expression_t *const ref = expr->array_access.array_ref;
1492                         mark_vars_read(ref, lhs_ent);
1493                         lhs_ent = determine_lhs_ent(ref, lhs_ent);
1494                         mark_vars_read(expr->array_access.index, lhs_ent);
1495                         return;
1496                 }
1497
1498                 case EXPR_VA_ARG:
1499                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1500                         return;
1501
1502                 case EXPR_VA_COPY:
1503                         mark_vars_read(expr->va_copye.src, lhs_ent);
1504                         return;
1505
1506                 case EXPR_UNARY_CAST:
1507                         /* Special case: Use void cast to mark a variable as "read" */
1508                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
1509                                 lhs_ent = NULL;
1510                         goto unary;
1511
1512
1513                 case EXPR_UNARY_THROW:
1514                         if (expr->unary.value == NULL)
1515                                 return;
1516                         /* FALLTHROUGH */
1517                 case EXPR_UNARY_DEREFERENCE:
1518                 case EXPR_UNARY_DELETE:
1519                 case EXPR_UNARY_DELETE_ARRAY:
1520                         if (lhs_ent == ENT_ANY)
1521                                 lhs_ent = NULL;
1522                         goto unary;
1523
1524                 case EXPR_UNARY_NEGATE:
1525                 case EXPR_UNARY_PLUS:
1526                 case EXPR_UNARY_BITWISE_NEGATE:
1527                 case EXPR_UNARY_NOT:
1528                 case EXPR_UNARY_TAKE_ADDRESS:
1529                 case EXPR_UNARY_POSTFIX_INCREMENT:
1530                 case EXPR_UNARY_POSTFIX_DECREMENT:
1531                 case EXPR_UNARY_PREFIX_INCREMENT:
1532                 case EXPR_UNARY_PREFIX_DECREMENT:
1533                 case EXPR_UNARY_CAST_IMPLICIT:
1534                 case EXPR_UNARY_ASSUME:
1535 unary:
1536                         mark_vars_read(expr->unary.value, lhs_ent);
1537                         return;
1538
1539                 case EXPR_BINARY_ADD:
1540                 case EXPR_BINARY_SUB:
1541                 case EXPR_BINARY_MUL:
1542                 case EXPR_BINARY_DIV:
1543                 case EXPR_BINARY_MOD:
1544                 case EXPR_BINARY_EQUAL:
1545                 case EXPR_BINARY_NOTEQUAL:
1546                 case EXPR_BINARY_LESS:
1547                 case EXPR_BINARY_LESSEQUAL:
1548                 case EXPR_BINARY_GREATER:
1549                 case EXPR_BINARY_GREATEREQUAL:
1550                 case EXPR_BINARY_BITWISE_AND:
1551                 case EXPR_BINARY_BITWISE_OR:
1552                 case EXPR_BINARY_BITWISE_XOR:
1553                 case EXPR_BINARY_LOGICAL_AND:
1554                 case EXPR_BINARY_LOGICAL_OR:
1555                 case EXPR_BINARY_SHIFTLEFT:
1556                 case EXPR_BINARY_SHIFTRIGHT:
1557                 case EXPR_BINARY_COMMA:
1558                 case EXPR_BINARY_ISGREATER:
1559                 case EXPR_BINARY_ISGREATEREQUAL:
1560                 case EXPR_BINARY_ISLESS:
1561                 case EXPR_BINARY_ISLESSEQUAL:
1562                 case EXPR_BINARY_ISLESSGREATER:
1563                 case EXPR_BINARY_ISUNORDERED:
1564                         mark_vars_read(expr->binary.left,  lhs_ent);
1565                         mark_vars_read(expr->binary.right, lhs_ent);
1566                         return;
1567
1568                 case EXPR_BINARY_ASSIGN:
1569                 case EXPR_BINARY_MUL_ASSIGN:
1570                 case EXPR_BINARY_DIV_ASSIGN:
1571                 case EXPR_BINARY_MOD_ASSIGN:
1572                 case EXPR_BINARY_ADD_ASSIGN:
1573                 case EXPR_BINARY_SUB_ASSIGN:
1574                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1575                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1576                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1577                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1578                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1579                         if (lhs_ent == ENT_ANY)
1580                                 lhs_ent = NULL;
1581                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1582                         mark_vars_read(expr->binary.right, lhs_ent);
1583                         return;
1584                 }
1585
1586                 case EXPR_VA_START:
1587                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1588                         return;
1589
1590                 EXPR_LITERAL_CASES
1591                 case EXPR_UNKNOWN:
1592                 case EXPR_INVALID:
1593                 case EXPR_STRING_LITERAL:
1594                 case EXPR_WIDE_STRING_LITERAL:
1595                 case EXPR_COMPOUND_LITERAL: // TODO init?
1596                 case EXPR_SIZEOF:
1597                 case EXPR_CLASSIFY_TYPE:
1598                 case EXPR_ALIGNOF:
1599                 case EXPR_FUNCNAME:
1600                 case EXPR_BUILTIN_CONSTANT_P:
1601                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1602                 case EXPR_OFFSETOF:
1603                 case EXPR_STATEMENT: // TODO
1604                 case EXPR_LABEL_ADDRESS:
1605                 case EXPR_REFERENCE_ENUM_VALUE:
1606                         return;
1607         }
1608
1609         panic("unhandled expression");
1610 }
1611
1612 static designator_t *parse_designation(void)
1613 {
1614         designator_t  *result = NULL;
1615         designator_t **anchor = &result;
1616
1617         for (;;) {
1618                 designator_t *designator;
1619                 switch (token.type) {
1620                 case '[':
1621                         designator = allocate_ast_zero(sizeof(designator[0]));
1622                         designator->source_position = token.source_position;
1623                         next_token();
1624                         add_anchor_token(']');
1625                         designator->array_index = parse_constant_expression();
1626                         rem_anchor_token(']');
1627                         expect(']', end_error);
1628                         break;
1629                 case '.':
1630                         designator = allocate_ast_zero(sizeof(designator[0]));
1631                         designator->source_position = token.source_position;
1632                         next_token();
1633                         if (token.type != T_IDENTIFIER) {
1634                                 parse_error_expected("while parsing designator",
1635                                                      T_IDENTIFIER, NULL);
1636                                 return NULL;
1637                         }
1638                         designator->symbol = token.symbol;
1639                         next_token();
1640                         break;
1641                 default:
1642                         expect('=', end_error);
1643                         return result;
1644                 }
1645
1646                 assert(designator != NULL);
1647                 *anchor = designator;
1648                 anchor  = &designator->next;
1649         }
1650 end_error:
1651         return NULL;
1652 }
1653
1654 static initializer_t *initializer_from_string(array_type_t *const type,
1655                                               const string_t *const string)
1656 {
1657         /* TODO: check len vs. size of array type */
1658         (void) type;
1659
1660         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1661         initializer->string.string = *string;
1662
1663         return initializer;
1664 }
1665
1666 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1667                                                    const string_t *const string)
1668 {
1669         /* TODO: check len vs. size of array type */
1670         (void) type;
1671
1672         initializer_t *const initializer =
1673                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1674         initializer->wide_string.string = *string;
1675
1676         return initializer;
1677 }
1678
1679 /**
1680  * Build an initializer from a given expression.
1681  */
1682 static initializer_t *initializer_from_expression(type_t *orig_type,
1683                                                   expression_t *expression)
1684 {
1685         /* TODO check that expression is a constant expression */
1686
1687         /* §6.7.8.14/15 char array may be initialized by string literals */
1688         type_t *type           = skip_typeref(orig_type);
1689         type_t *expr_type_orig = expression->base.type;
1690         type_t *expr_type      = skip_typeref(expr_type_orig);
1691
1692         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1693                 array_type_t *const array_type   = &type->array;
1694                 type_t       *const element_type = skip_typeref(array_type->element_type);
1695
1696                 if (element_type->kind == TYPE_ATOMIC) {
1697                         atomic_type_kind_t akind = element_type->atomic.akind;
1698                         switch (expression->kind) {
1699                         case EXPR_STRING_LITERAL:
1700                                 if (akind == ATOMIC_TYPE_CHAR
1701                                                 || akind == ATOMIC_TYPE_SCHAR
1702                                                 || akind == ATOMIC_TYPE_UCHAR) {
1703                                         return initializer_from_string(array_type,
1704                                                         &expression->string_literal.value);
1705                                 }
1706                                 break;
1707
1708                         case EXPR_WIDE_STRING_LITERAL: {
1709                                 type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1710                                 if (get_unqualified_type(element_type) == bare_wchar_type) {
1711                                         return initializer_from_wide_string(array_type,
1712                                                         &expression->string_literal.value);
1713                                 }
1714                                 break;
1715                         }
1716
1717                         default:
1718                                 break;
1719                         }
1720                 }
1721         }
1722
1723         assign_error_t error = semantic_assign(type, expression);
1724         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1725                 return NULL;
1726         report_assign_error(error, type, expression, "initializer",
1727                             &expression->base.source_position);
1728
1729         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1730         result->value.value = create_implicit_cast(expression, type);
1731
1732         return result;
1733 }
1734
1735 /**
1736  * Checks if a given expression can be used as an constant initializer.
1737  */
1738 static bool is_initializer_constant(const expression_t *expression)
1739 {
1740         return
1741                 is_constant_expression(expression) != EXPR_CLASS_VARIABLE ||
1742                 is_address_constant(expression)    != EXPR_CLASS_VARIABLE;
1743 }
1744
1745 /**
1746  * Parses an scalar initializer.
1747  *
1748  * §6.7.8.11; eat {} without warning
1749  */
1750 static initializer_t *parse_scalar_initializer(type_t *type,
1751                                                bool must_be_constant)
1752 {
1753         /* there might be extra {} hierarchies */
1754         int braces = 0;
1755         if (next_if('{')) {
1756                 if (warning.other)
1757                         warningf(HERE, "extra curly braces around scalar initializer");
1758                 do {
1759                         ++braces;
1760                 } while (next_if('{'));
1761         }
1762
1763         expression_t *expression = parse_assignment_expression();
1764         mark_vars_read(expression, NULL);
1765         if (must_be_constant && !is_initializer_constant(expression)) {
1766                 errorf(&expression->base.source_position,
1767                        "initialisation expression '%E' is not constant",
1768                        expression);
1769         }
1770
1771         initializer_t *initializer = initializer_from_expression(type, expression);
1772
1773         if (initializer == NULL) {
1774                 errorf(&expression->base.source_position,
1775                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1776                        expression, expression->base.type, type);
1777                 /* TODO */
1778                 return NULL;
1779         }
1780
1781         bool additional_warning_displayed = false;
1782         while (braces > 0) {
1783                 next_if(',');
1784                 if (token.type != '}') {
1785                         if (!additional_warning_displayed && warning.other) {
1786                                 warningf(HERE, "additional elements in scalar initializer");
1787                                 additional_warning_displayed = true;
1788                         }
1789                 }
1790                 eat_block();
1791                 braces--;
1792         }
1793
1794         return initializer;
1795 }
1796
1797 /**
1798  * An entry in the type path.
1799  */
1800 typedef struct type_path_entry_t type_path_entry_t;
1801 struct type_path_entry_t {
1802         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1803         union {
1804                 size_t         index;          /**< For array types: the current index. */
1805                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1806         } v;
1807 };
1808
1809 /**
1810  * A type path expression a position inside compound or array types.
1811  */
1812 typedef struct type_path_t type_path_t;
1813 struct type_path_t {
1814         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1815         type_t            *top_type;     /**< type of the element the path points */
1816         size_t             max_index;    /**< largest index in outermost array */
1817 };
1818
1819 /**
1820  * Prints a type path for debugging.
1821  */
1822 static __attribute__((unused)) void debug_print_type_path(
1823                 const type_path_t *path)
1824 {
1825         size_t len = ARR_LEN(path->path);
1826
1827         for (size_t i = 0; i < len; ++i) {
1828                 const type_path_entry_t *entry = & path->path[i];
1829
1830                 type_t *type = skip_typeref(entry->type);
1831                 if (is_type_compound(type)) {
1832                         /* in gcc mode structs can have no members */
1833                         if (entry->v.compound_entry == NULL) {
1834                                 assert(i == len-1);
1835                                 continue;
1836                         }
1837                         fprintf(stderr, ".%s",
1838                                 entry->v.compound_entry->base.symbol->string);
1839                 } else if (is_type_array(type)) {
1840                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1841                 } else {
1842                         fprintf(stderr, "-INVALID-");
1843                 }
1844         }
1845         if (path->top_type != NULL) {
1846                 fprintf(stderr, "  (");
1847                 print_type(path->top_type);
1848                 fprintf(stderr, ")");
1849         }
1850 }
1851
1852 /**
1853  * Return the top type path entry, ie. in a path
1854  * (type).a.b returns the b.
1855  */
1856 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1857 {
1858         size_t len = ARR_LEN(path->path);
1859         assert(len > 0);
1860         return &path->path[len-1];
1861 }
1862
1863 /**
1864  * Enlarge the type path by an (empty) element.
1865  */
1866 static type_path_entry_t *append_to_type_path(type_path_t *path)
1867 {
1868         size_t len = ARR_LEN(path->path);
1869         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1870
1871         type_path_entry_t *result = & path->path[len];
1872         memset(result, 0, sizeof(result[0]));
1873         return result;
1874 }
1875
1876 /**
1877  * Descending into a sub-type. Enter the scope of the current top_type.
1878  */
1879 static void descend_into_subtype(type_path_t *path)
1880 {
1881         type_t *orig_top_type = path->top_type;
1882         type_t *top_type      = skip_typeref(orig_top_type);
1883
1884         type_path_entry_t *top = append_to_type_path(path);
1885         top->type              = top_type;
1886
1887         if (is_type_compound(top_type)) {
1888                 compound_t *compound  = top_type->compound.compound;
1889                 entity_t   *entry     = compound->members.entities;
1890
1891                 if (entry != NULL) {
1892                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
1893                         top->v.compound_entry = &entry->declaration;
1894                         path->top_type = entry->declaration.type;
1895                 } else {
1896                         path->top_type = NULL;
1897                 }
1898         } else if (is_type_array(top_type)) {
1899                 top->v.index   = 0;
1900                 path->top_type = top_type->array.element_type;
1901         } else {
1902                 assert(!is_type_valid(top_type));
1903         }
1904 }
1905
1906 /**
1907  * Pop an entry from the given type path, ie. returning from
1908  * (type).a.b to (type).a
1909  */
1910 static void ascend_from_subtype(type_path_t *path)
1911 {
1912         type_path_entry_t *top = get_type_path_top(path);
1913
1914         path->top_type = top->type;
1915
1916         size_t len = ARR_LEN(path->path);
1917         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1918 }
1919
1920 /**
1921  * Pop entries from the given type path until the given
1922  * path level is reached.
1923  */
1924 static void ascend_to(type_path_t *path, size_t top_path_level)
1925 {
1926         size_t len = ARR_LEN(path->path);
1927
1928         while (len > top_path_level) {
1929                 ascend_from_subtype(path);
1930                 len = ARR_LEN(path->path);
1931         }
1932 }
1933
1934 static bool walk_designator(type_path_t *path, const designator_t *designator,
1935                             bool used_in_offsetof)
1936 {
1937         for (; designator != NULL; designator = designator->next) {
1938                 type_path_entry_t *top       = get_type_path_top(path);
1939                 type_t            *orig_type = top->type;
1940
1941                 type_t *type = skip_typeref(orig_type);
1942
1943                 if (designator->symbol != NULL) {
1944                         symbol_t *symbol = designator->symbol;
1945                         if (!is_type_compound(type)) {
1946                                 if (is_type_valid(type)) {
1947                                         errorf(&designator->source_position,
1948                                                "'.%Y' designator used for non-compound type '%T'",
1949                                                symbol, orig_type);
1950                                 }
1951
1952                                 top->type             = type_error_type;
1953                                 top->v.compound_entry = NULL;
1954                                 orig_type             = type_error_type;
1955                         } else {
1956                                 compound_t *compound = type->compound.compound;
1957                                 entity_t   *iter     = compound->members.entities;
1958                                 for (; iter != NULL; iter = iter->base.next) {
1959                                         if (iter->base.symbol == symbol) {
1960                                                 break;
1961                                         }
1962                                 }
1963                                 if (iter == NULL) {
1964                                         errorf(&designator->source_position,
1965                                                "'%T' has no member named '%Y'", orig_type, symbol);
1966                                         return false;
1967                                 }
1968                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1969                                 if (used_in_offsetof) {
1970                                         type_t *real_type = skip_typeref(iter->declaration.type);
1971                                         if (real_type->kind == TYPE_BITFIELD) {
1972                                                 errorf(&designator->source_position,
1973                                                        "offsetof designator '%Y' must not specify bitfield",
1974                                                        symbol);
1975                                                 return false;
1976                                         }
1977                                 }
1978
1979                                 top->type             = orig_type;
1980                                 top->v.compound_entry = &iter->declaration;
1981                                 orig_type             = iter->declaration.type;
1982                         }
1983                 } else {
1984                         expression_t *array_index = designator->array_index;
1985                         assert(designator->array_index != NULL);
1986
1987                         if (!is_type_array(type)) {
1988                                 if (is_type_valid(type)) {
1989                                         errorf(&designator->source_position,
1990                                                "[%E] designator used for non-array type '%T'",
1991                                                array_index, orig_type);
1992                                 }
1993                                 return false;
1994                         }
1995
1996                         long index = fold_constant_to_int(array_index);
1997                         if (!used_in_offsetof) {
1998                                 if (index < 0) {
1999                                         errorf(&designator->source_position,
2000                                                "array index [%E] must be positive", array_index);
2001                                 } else if (type->array.size_constant) {
2002                                         long array_size = type->array.size;
2003                                         if (index >= array_size) {
2004                                                 errorf(&designator->source_position,
2005                                                        "designator [%E] (%d) exceeds array size %d",
2006                                                        array_index, index, array_size);
2007                                         }
2008                                 }
2009                         }
2010
2011                         top->type    = orig_type;
2012                         top->v.index = (size_t) index;
2013                         orig_type    = type->array.element_type;
2014                 }
2015                 path->top_type = orig_type;
2016
2017                 if (designator->next != NULL) {
2018                         descend_into_subtype(path);
2019                 }
2020         }
2021         return true;
2022 }
2023
2024 static void advance_current_object(type_path_t *path, size_t top_path_level)
2025 {
2026         type_path_entry_t *top = get_type_path_top(path);
2027
2028         type_t *type = skip_typeref(top->type);
2029         if (is_type_union(type)) {
2030                 /* in unions only the first element is initialized */
2031                 top->v.compound_entry = NULL;
2032         } else if (is_type_struct(type)) {
2033                 declaration_t *entry = top->v.compound_entry;
2034
2035                 entity_t *next_entity = entry->base.next;
2036                 if (next_entity != NULL) {
2037                         assert(is_declaration(next_entity));
2038                         entry = &next_entity->declaration;
2039                 } else {
2040                         entry = NULL;
2041                 }
2042
2043                 top->v.compound_entry = entry;
2044                 if (entry != NULL) {
2045                         path->top_type = entry->type;
2046                         return;
2047                 }
2048         } else if (is_type_array(type)) {
2049                 assert(is_type_array(type));
2050
2051                 top->v.index++;
2052
2053                 if (!type->array.size_constant || top->v.index < type->array.size) {
2054                         return;
2055                 }
2056         } else {
2057                 assert(!is_type_valid(type));
2058                 return;
2059         }
2060
2061         /* we're past the last member of the current sub-aggregate, try if we
2062          * can ascend in the type hierarchy and continue with another subobject */
2063         size_t len = ARR_LEN(path->path);
2064
2065         if (len > top_path_level) {
2066                 ascend_from_subtype(path);
2067                 advance_current_object(path, top_path_level);
2068         } else {
2069                 path->top_type = NULL;
2070         }
2071 }
2072
2073 /**
2074  * skip any {...} blocks until a closing bracket is reached.
2075  */
2076 static void skip_initializers(void)
2077 {
2078         next_if('{');
2079
2080         while (token.type != '}') {
2081                 if (token.type == T_EOF)
2082                         return;
2083                 if (token.type == '{') {
2084                         eat_block();
2085                         continue;
2086                 }
2087                 next_token();
2088         }
2089 }
2090
2091 static initializer_t *create_empty_initializer(void)
2092 {
2093         static initializer_t empty_initializer
2094                 = { .list = { { INITIALIZER_LIST }, 0 } };
2095         return &empty_initializer;
2096 }
2097
2098 /**
2099  * Parse a part of an initialiser for a struct or union,
2100  */
2101 static initializer_t *parse_sub_initializer(type_path_t *path,
2102                 type_t *outer_type, size_t top_path_level,
2103                 parse_initializer_env_t *env)
2104 {
2105         if (token.type == '}') {
2106                 /* empty initializer */
2107                 return create_empty_initializer();
2108         }
2109
2110         type_t *orig_type = path->top_type;
2111         type_t *type      = NULL;
2112
2113         if (orig_type == NULL) {
2114                 /* We are initializing an empty compound. */
2115         } else {
2116                 type = skip_typeref(orig_type);
2117         }
2118
2119         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2120
2121         while (true) {
2122                 designator_t *designator = NULL;
2123                 if (token.type == '.' || token.type == '[') {
2124                         designator = parse_designation();
2125                         goto finish_designator;
2126                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2127                         /* GNU-style designator ("identifier: value") */
2128                         designator = allocate_ast_zero(sizeof(designator[0]));
2129                         designator->source_position = token.source_position;
2130                         designator->symbol          = token.symbol;
2131                         eat(T_IDENTIFIER);
2132                         eat(':');
2133
2134 finish_designator:
2135                         /* reset path to toplevel, evaluate designator from there */
2136                         ascend_to(path, top_path_level);
2137                         if (!walk_designator(path, designator, false)) {
2138                                 /* can't continue after designation error */
2139                                 goto end_error;
2140                         }
2141
2142                         initializer_t *designator_initializer
2143                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2144                         designator_initializer->designator.designator = designator;
2145                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2146
2147                         orig_type = path->top_type;
2148                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2149                 }
2150
2151                 initializer_t *sub;
2152
2153                 if (token.type == '{') {
2154                         if (type != NULL && is_type_scalar(type)) {
2155                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2156                         } else {
2157                                 eat('{');
2158                                 if (type == NULL) {
2159                                         if (env->entity != NULL) {
2160                                                 errorf(HERE,
2161                                                      "extra brace group at end of initializer for '%Y'",
2162                                                      env->entity->base.symbol);
2163                                         } else {
2164                                                 errorf(HERE, "extra brace group at end of initializer");
2165                                         }
2166                                 } else
2167                                         descend_into_subtype(path);
2168
2169                                 add_anchor_token('}');
2170                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2171                                                             env);
2172                                 rem_anchor_token('}');
2173
2174                                 if (type != NULL) {
2175                                         ascend_from_subtype(path);
2176                                         expect('}', end_error);
2177                                 } else {
2178                                         expect('}', end_error);
2179                                         goto error_parse_next;
2180                                 }
2181                         }
2182                 } else {
2183                         /* must be an expression */
2184                         expression_t *expression = parse_assignment_expression();
2185                         mark_vars_read(expression, NULL);
2186
2187                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2188                                 errorf(&expression->base.source_position,
2189                                        "Initialisation expression '%E' is not constant",
2190                                        expression);
2191                         }
2192
2193                         if (type == NULL) {
2194                                 /* we are already outside, ... */
2195                                 if (outer_type == NULL)
2196                                         goto error_parse_next;
2197                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2198                                 if (is_type_compound(outer_type_skip) &&
2199                                     !outer_type_skip->compound.compound->complete) {
2200                                         goto error_parse_next;
2201                                 }
2202                                 goto error_excess;
2203                         }
2204
2205                         /* handle { "string" } special case */
2206                         if ((expression->kind == EXPR_STRING_LITERAL
2207                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2208                                         && outer_type != NULL) {
2209                                 sub = initializer_from_expression(outer_type, expression);
2210                                 if (sub != NULL) {
2211                                         next_if(',');
2212                                         if (token.type != '}' && warning.other) {
2213                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2214                                                                  orig_type);
2215                                         }
2216                                         /* TODO: eat , ... */
2217                                         return sub;
2218                                 }
2219                         }
2220
2221                         /* descend into subtypes until expression matches type */
2222                         while (true) {
2223                                 orig_type = path->top_type;
2224                                 type      = skip_typeref(orig_type);
2225
2226                                 sub = initializer_from_expression(orig_type, expression);
2227                                 if (sub != NULL) {
2228                                         break;
2229                                 }
2230                                 if (!is_type_valid(type)) {
2231                                         goto end_error;
2232                                 }
2233                                 if (is_type_scalar(type)) {
2234                                         errorf(&expression->base.source_position,
2235                                                         "expression '%E' doesn't match expected type '%T'",
2236                                                         expression, orig_type);
2237                                         goto end_error;
2238                                 }
2239
2240                                 descend_into_subtype(path);
2241                         }
2242                 }
2243
2244                 /* update largest index of top array */
2245                 const type_path_entry_t *first      = &path->path[0];
2246                 type_t                  *first_type = first->type;
2247                 first_type                          = skip_typeref(first_type);
2248                 if (is_type_array(first_type)) {
2249                         size_t index = first->v.index;
2250                         if (index > path->max_index)
2251                                 path->max_index = index;
2252                 }
2253
2254                 if (type != NULL) {
2255                         /* append to initializers list */
2256                         ARR_APP1(initializer_t*, initializers, sub);
2257                 } else {
2258 error_excess:
2259                         if (warning.other) {
2260                                 if (env->entity != NULL) {
2261                                         warningf(HERE, "excess elements in initializer for '%Y'",
2262                                                  env->entity->base.symbol);
2263                                 } else {
2264                                         warningf(HERE, "excess elements in initializer");
2265                                 }
2266                         }
2267                 }
2268
2269 error_parse_next:
2270                 if (token.type == '}') {
2271                         break;
2272                 }
2273                 expect(',', end_error);
2274                 if (token.type == '}') {
2275                         break;
2276                 }
2277
2278                 if (type != NULL) {
2279                         /* advance to the next declaration if we are not at the end */
2280                         advance_current_object(path, top_path_level);
2281                         orig_type = path->top_type;
2282                         if (orig_type != NULL)
2283                                 type = skip_typeref(orig_type);
2284                         else
2285                                 type = NULL;
2286                 }
2287         }
2288
2289         size_t len  = ARR_LEN(initializers);
2290         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2291         initializer_t *result = allocate_ast_zero(size);
2292         result->kind          = INITIALIZER_LIST;
2293         result->list.len      = len;
2294         memcpy(&result->list.initializers, initializers,
2295                len * sizeof(initializers[0]));
2296
2297         DEL_ARR_F(initializers);
2298         ascend_to(path, top_path_level+1);
2299
2300         return result;
2301
2302 end_error:
2303         skip_initializers();
2304         DEL_ARR_F(initializers);
2305         ascend_to(path, top_path_level+1);
2306         return NULL;
2307 }
2308
2309 static expression_t *make_size_literal(size_t value)
2310 {
2311         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2312         literal->base.type    = type_size_t;
2313
2314         char buf[128];
2315         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2316         literal->literal.value = make_string(buf);
2317
2318         return literal;
2319 }
2320
2321 /**
2322  * Parses an initializer. Parsers either a compound literal
2323  * (env->declaration == NULL) or an initializer of a declaration.
2324  */
2325 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2326 {
2327         type_t        *type      = skip_typeref(env->type);
2328         size_t         max_index = 0;
2329         initializer_t *result;
2330
2331         if (is_type_scalar(type)) {
2332                 result = parse_scalar_initializer(type, env->must_be_constant);
2333         } else if (token.type == '{') {
2334                 eat('{');
2335
2336                 type_path_t path;
2337                 memset(&path, 0, sizeof(path));
2338                 path.top_type = env->type;
2339                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2340
2341                 descend_into_subtype(&path);
2342
2343                 add_anchor_token('}');
2344                 result = parse_sub_initializer(&path, env->type, 1, env);
2345                 rem_anchor_token('}');
2346
2347                 max_index = path.max_index;
2348                 DEL_ARR_F(path.path);
2349
2350                 expect('}', end_error);
2351         } else {
2352                 /* parse_scalar_initializer() also works in this case: we simply
2353                  * have an expression without {} around it */
2354                 result = parse_scalar_initializer(type, env->must_be_constant);
2355         }
2356
2357         /* §6.7.8:22 array initializers for arrays with unknown size determine
2358          * the array type size */
2359         if (is_type_array(type) && type->array.size_expression == NULL
2360                         && result != NULL) {
2361                 size_t size;
2362                 switch (result->kind) {
2363                 case INITIALIZER_LIST:
2364                         assert(max_index != 0xdeadbeaf);
2365                         size = max_index + 1;
2366                         break;
2367
2368                 case INITIALIZER_STRING:
2369                         size = result->string.string.size;
2370                         break;
2371
2372                 case INITIALIZER_WIDE_STRING:
2373                         size = result->wide_string.string.size;
2374                         break;
2375
2376                 case INITIALIZER_DESIGNATOR:
2377                 case INITIALIZER_VALUE:
2378                         /* can happen for parse errors */
2379                         size = 0;
2380                         break;
2381
2382                 default:
2383                         internal_errorf(HERE, "invalid initializer type");
2384                 }
2385
2386                 type_t *new_type = duplicate_type(type);
2387
2388                 new_type->array.size_expression   = make_size_literal(size);
2389                 new_type->array.size_constant     = true;
2390                 new_type->array.has_implicit_size = true;
2391                 new_type->array.size              = size;
2392                 env->type = new_type;
2393         }
2394
2395         return result;
2396 end_error:
2397         return NULL;
2398 }
2399
2400 static void append_entity(scope_t *scope, entity_t *entity)
2401 {
2402         if (scope->last_entity != NULL) {
2403                 scope->last_entity->base.next = entity;
2404         } else {
2405                 scope->entities = entity;
2406         }
2407         entity->base.parent_entity = current_entity;
2408         scope->last_entity         = entity;
2409 }
2410
2411
2412 static compound_t *parse_compound_type_specifier(bool is_struct)
2413 {
2414         eat(is_struct ? T_struct : T_union);
2415
2416         symbol_t    *symbol     = NULL;
2417         entity_t    *entity     = NULL;
2418         attribute_t *attributes = NULL;
2419
2420         if (token.type == T___attribute__) {
2421                 attributes = parse_attributes(NULL);
2422         }
2423
2424         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2425         if (token.type == T_IDENTIFIER) {
2426                 /* the compound has a name, check if we have seen it already */
2427                 symbol = token.symbol;
2428                 next_token();
2429
2430                 entity = get_tag(symbol, kind);
2431                 if (entity != NULL) {
2432                         if (entity->base.parent_scope != current_scope &&
2433                             (token.type == '{' || token.type == ';')) {
2434                                 /* we're in an inner scope and have a definition. Shadow
2435                                  * existing definition in outer scope */
2436                                 entity = NULL;
2437                         } else if (entity->compound.complete && token.type == '{') {
2438                                 assert(symbol != NULL);
2439                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition %P)",
2440                                        is_struct ? "struct" : "union", symbol,
2441                                        &entity->base.source_position);
2442                                 /* clear members in the hope to avoid further errors */
2443                                 entity->compound.members.entities = NULL;
2444                         }
2445                 }
2446         } else if (token.type != '{') {
2447                 if (is_struct) {
2448                         parse_error_expected("while parsing struct type specifier",
2449                                              T_IDENTIFIER, '{', NULL);
2450                 } else {
2451                         parse_error_expected("while parsing union type specifier",
2452                                              T_IDENTIFIER, '{', NULL);
2453                 }
2454
2455                 return NULL;
2456         }
2457
2458         if (entity == NULL) {
2459                 entity = allocate_entity_zero(kind);
2460
2461                 entity->compound.alignment   = 1;
2462                 entity->base.namespc         = NAMESPACE_TAG;
2463                 entity->base.source_position = token.source_position;
2464                 entity->base.symbol          = symbol;
2465                 entity->base.parent_scope    = current_scope;
2466                 if (symbol != NULL) {
2467                         environment_push(entity);
2468                 }
2469                 append_entity(current_scope, entity);
2470         }
2471
2472         if (token.type == '{') {
2473                 parse_compound_type_entries(&entity->compound);
2474
2475                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2476                 if (symbol == NULL) {
2477                         assert(anonymous_entity == NULL);
2478                         anonymous_entity = entity;
2479                 }
2480         }
2481
2482         if (attributes != NULL) {
2483                 handle_entity_attributes(attributes, entity);
2484         }
2485
2486         return &entity->compound;
2487 }
2488
2489 static void parse_enum_entries(type_t *const enum_type)
2490 {
2491         eat('{');
2492
2493         if (token.type == '}') {
2494                 errorf(HERE, "empty enum not allowed");
2495                 next_token();
2496                 return;
2497         }
2498
2499         add_anchor_token('}');
2500         do {
2501                 if (token.type != T_IDENTIFIER) {
2502                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
2503                         eat_block();
2504                         rem_anchor_token('}');
2505                         return;
2506                 }
2507
2508                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
2509                 entity->enum_value.enum_type = enum_type;
2510                 entity->base.namespc         = NAMESPACE_NORMAL;
2511                 entity->base.symbol          = token.symbol;
2512                 entity->base.source_position = token.source_position;
2513                 next_token();
2514
2515                 if (next_if('=')) {
2516                         expression_t *value = parse_constant_expression();
2517
2518                         value = create_implicit_cast(value, enum_type);
2519                         entity->enum_value.value = value;
2520
2521                         /* TODO semantic */
2522                 }
2523
2524                 record_entity(entity, false);
2525         } while (next_if(',') && token.type != '}');
2526         rem_anchor_token('}');
2527
2528         expect('}', end_error);
2529
2530 end_error:
2531         ;
2532 }
2533
2534 static type_t *parse_enum_specifier(void)
2535 {
2536         entity_t *entity;
2537         symbol_t *symbol;
2538
2539         eat(T_enum);
2540         switch (token.type) {
2541                 case T_IDENTIFIER:
2542                         symbol = token.symbol;
2543                         next_token();
2544
2545                         entity = get_tag(symbol, ENTITY_ENUM);
2546                         if (entity != NULL) {
2547                                 if (entity->base.parent_scope != current_scope &&
2548                                                 (token.type == '{' || token.type == ';')) {
2549                                         /* we're in an inner scope and have a definition. Shadow
2550                                          * existing definition in outer scope */
2551                                         entity = NULL;
2552                                 } else if (entity->enume.complete && token.type == '{') {
2553                                         errorf(HERE, "multiple definitions of 'enum %Y' (previous definition %P)",
2554                                                         symbol, &entity->base.source_position);
2555                                 }
2556                         }
2557                         break;
2558
2559                 case '{':
2560                         entity = NULL;
2561                         symbol = NULL;
2562                         break;
2563
2564                 default:
2565                         parse_error_expected("while parsing enum type specifier",
2566                                         T_IDENTIFIER, '{', NULL);
2567                         return NULL;
2568         }
2569
2570         if (entity == NULL) {
2571                 entity                       = allocate_entity_zero(ENTITY_ENUM);
2572                 entity->base.namespc         = NAMESPACE_TAG;
2573                 entity->base.source_position = token.source_position;
2574                 entity->base.symbol          = symbol;
2575                 entity->base.parent_scope    = current_scope;
2576         }
2577
2578         type_t *const type = allocate_type_zero(TYPE_ENUM);
2579         type->enumt.enume  = &entity->enume;
2580         type->enumt.akind  = ATOMIC_TYPE_INT;
2581
2582         if (token.type == '{') {
2583                 if (symbol != NULL) {
2584                         environment_push(entity);
2585                 }
2586                 append_entity(current_scope, entity);
2587                 entity->enume.complete = true;
2588
2589                 parse_enum_entries(type);
2590                 parse_attributes(NULL);
2591
2592                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2593                 if (symbol == NULL) {
2594                         assert(anonymous_entity == NULL);
2595                         anonymous_entity = entity;
2596                 }
2597         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2598                 errorf(HERE, "'enum %Y' used before definition (incomplete enums are a GNU extension)",
2599                        symbol);
2600         }
2601
2602         return type;
2603 }
2604
2605 /**
2606  * if a symbol is a typedef to another type, return true
2607  */
2608 static bool is_typedef_symbol(symbol_t *symbol)
2609 {
2610         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2611         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2612 }
2613
2614 static type_t *parse_typeof(void)
2615 {
2616         eat(T___typeof__);
2617
2618         type_t *type;
2619
2620         expect('(', end_error);
2621         add_anchor_token(')');
2622
2623         expression_t *expression  = NULL;
2624
2625         bool old_type_prop     = in_type_prop;
2626         bool old_gcc_extension = in_gcc_extension;
2627         in_type_prop           = true;
2628
2629         while (next_if(T___extension__)) {
2630                 /* This can be a prefix to a typename or an expression. */
2631                 in_gcc_extension = true;
2632         }
2633         switch (token.type) {
2634         case T_IDENTIFIER:
2635                 if (is_typedef_symbol(token.symbol)) {
2636         TYPENAME_START
2637                         type = parse_typename();
2638                 } else {
2639         default:
2640                         expression = parse_expression();
2641                         type       = revert_automatic_type_conversion(expression);
2642                 }
2643                 break;
2644         }
2645         in_type_prop     = old_type_prop;
2646         in_gcc_extension = old_gcc_extension;
2647
2648         rem_anchor_token(')');
2649         expect(')', end_error);
2650
2651         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2652         typeof_type->typeoft.expression  = expression;
2653         typeof_type->typeoft.typeof_type = type;
2654
2655         return typeof_type;
2656 end_error:
2657         return NULL;
2658 }
2659
2660 typedef enum specifiers_t {
2661         SPECIFIER_SIGNED    = 1 << 0,
2662         SPECIFIER_UNSIGNED  = 1 << 1,
2663         SPECIFIER_LONG      = 1 << 2,
2664         SPECIFIER_INT       = 1 << 3,
2665         SPECIFIER_DOUBLE    = 1 << 4,
2666         SPECIFIER_CHAR      = 1 << 5,
2667         SPECIFIER_WCHAR_T   = 1 << 6,
2668         SPECIFIER_SHORT     = 1 << 7,
2669         SPECIFIER_LONG_LONG = 1 << 8,
2670         SPECIFIER_FLOAT     = 1 << 9,
2671         SPECIFIER_BOOL      = 1 << 10,
2672         SPECIFIER_VOID      = 1 << 11,
2673         SPECIFIER_INT8      = 1 << 12,
2674         SPECIFIER_INT16     = 1 << 13,
2675         SPECIFIER_INT32     = 1 << 14,
2676         SPECIFIER_INT64     = 1 << 15,
2677         SPECIFIER_INT128    = 1 << 16,
2678         SPECIFIER_COMPLEX   = 1 << 17,
2679         SPECIFIER_IMAGINARY = 1 << 18,
2680 } specifiers_t;
2681
2682 static type_t *get_typedef_type(symbol_t *symbol)
2683 {
2684         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2685         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2686                 return NULL;
2687
2688         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2689         type->typedeft.typedefe = &entity->typedefe;
2690
2691         return type;
2692 }
2693
2694 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2695 {
2696         expect('(', end_error);
2697
2698         attribute_property_argument_t *property
2699                 = allocate_ast_zero(sizeof(*property));
2700
2701         do {
2702                 if (token.type != T_IDENTIFIER) {
2703                         parse_error_expected("while parsing property declspec",
2704                                              T_IDENTIFIER, NULL);
2705                         goto end_error;
2706                 }
2707
2708                 bool is_put;
2709                 symbol_t *symbol = token.symbol;
2710                 next_token();
2711                 if (strcmp(symbol->string, "put") == 0) {
2712                         is_put = true;
2713                 } else if (strcmp(symbol->string, "get") == 0) {
2714                         is_put = false;
2715                 } else {
2716                         errorf(HERE, "expected put or get in property declspec");
2717                         goto end_error;
2718                 }
2719                 expect('=', end_error);
2720                 if (token.type != T_IDENTIFIER) {
2721                         parse_error_expected("while parsing property declspec",
2722                                              T_IDENTIFIER, NULL);
2723                         goto end_error;
2724                 }
2725                 if (is_put) {
2726                         property->put_symbol = token.symbol;
2727                 } else {
2728                         property->get_symbol = token.symbol;
2729                 }
2730                 next_token();
2731         } while (next_if(','));
2732
2733         attribute->a.property = property;
2734
2735         expect(')', end_error);
2736
2737 end_error:
2738         return attribute;
2739 }
2740
2741 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2742 {
2743         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2744         if (next_if(T_restrict)) {
2745                 kind = ATTRIBUTE_MS_RESTRICT;
2746         } else if (token.type == T_IDENTIFIER) {
2747                 const char *name = token.symbol->string;
2748                 next_token();
2749                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2750                      ++k) {
2751                         const char *attribute_name = get_attribute_name(k);
2752                         if (attribute_name != NULL && strcmp(attribute_name, name) == 0) {
2753                                 kind = k;
2754                                 break;
2755                         }
2756                 }
2757
2758                 if (kind == ATTRIBUTE_UNKNOWN && warning.attribute) {
2759                         warningf(HERE, "unknown __declspec '%s' ignored", name);
2760                 }
2761         } else {
2762                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2763                 return NULL;
2764         }
2765
2766         attribute_t *attribute = allocate_attribute_zero(kind);
2767
2768         if (kind == ATTRIBUTE_MS_PROPERTY) {
2769                 return parse_attribute_ms_property(attribute);
2770         }
2771
2772         /* parse arguments */
2773         if (next_if('('))
2774                 attribute->a.arguments = parse_attribute_arguments();
2775
2776         return attribute;
2777 }
2778
2779 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2780 {
2781         eat(T__declspec);
2782
2783         expect('(', end_error);
2784
2785         if (next_if(')'))
2786                 return NULL;
2787
2788         add_anchor_token(')');
2789
2790         attribute_t **anchor = &first;
2791         do {
2792                 while (*anchor != NULL)
2793                         anchor = &(*anchor)->next;
2794
2795                 attribute_t *attribute
2796                         = parse_microsoft_extended_decl_modifier_single();
2797                 if (attribute == NULL)
2798                         goto end_error;
2799
2800                 *anchor = attribute;
2801                 anchor  = &attribute->next;
2802         } while (next_if(','));
2803
2804         rem_anchor_token(')');
2805         expect(')', end_error);
2806         return first;
2807
2808 end_error:
2809         rem_anchor_token(')');
2810         return first;
2811 }
2812
2813 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2814 {
2815         entity_t *entity             = allocate_entity_zero(kind);
2816         entity->base.namespc         = NAMESPACE_NORMAL;
2817         entity->base.source_position = *HERE;
2818         entity->base.symbol          = symbol;
2819         if (is_declaration(entity)) {
2820                 entity->declaration.type     = type_error_type;
2821                 entity->declaration.implicit = true;
2822         } else if (kind == ENTITY_TYPEDEF) {
2823                 entity->typedefe.type    = type_error_type;
2824                 entity->typedefe.builtin = true;
2825         }
2826         if (kind != ENTITY_COMPOUND_MEMBER)
2827                 record_entity(entity, false);
2828         return entity;
2829 }
2830
2831 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2832 {
2833         type_t            *type              = NULL;
2834         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
2835         unsigned           type_specifiers   = 0;
2836         bool               newtype           = false;
2837         bool               saw_error         = false;
2838         bool               old_gcc_extension = in_gcc_extension;
2839
2840         specifiers->source_position = token.source_position;
2841
2842         while (true) {
2843                 specifiers->attributes = parse_attributes(specifiers->attributes);
2844
2845                 switch (token.type) {
2846                 /* storage class */
2847 #define MATCH_STORAGE_CLASS(token, class)                                  \
2848                 case token:                                                        \
2849                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2850                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2851                         }                                                              \
2852                         specifiers->storage_class = class;                             \
2853                         if (specifiers->thread_local)                                  \
2854                                 goto check_thread_storage_class;                           \
2855                         next_token();                                                  \
2856                         break;
2857
2858                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2859                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2860                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2861                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2862                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2863
2864                 case T__declspec:
2865                         specifiers->attributes
2866                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2867                         break;
2868
2869                 case T___thread:
2870                         if (specifiers->thread_local) {
2871                                 errorf(HERE, "duplicate '__thread'");
2872                         } else {
2873                                 specifiers->thread_local = true;
2874 check_thread_storage_class:
2875                                 switch (specifiers->storage_class) {
2876                                         case STORAGE_CLASS_EXTERN:
2877                                         case STORAGE_CLASS_NONE:
2878                                         case STORAGE_CLASS_STATIC:
2879                                                 break;
2880
2881                                                 char const* wrong;
2882                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2883                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2884                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2885 wrong_thread_storage_class:
2886                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2887                                                 break;
2888                                 }
2889                         }
2890                         next_token();
2891                         break;
2892
2893                 /* type qualifiers */
2894 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2895                 case token:                                                     \
2896                         qualifiers |= qualifier;                                    \
2897                         next_token();                                               \
2898                         break
2899
2900                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2901                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2902                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2903                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2904                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2905                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2906                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2907                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2908
2909                 case T___extension__:
2910                         next_token();
2911                         in_gcc_extension = true;
2912                         break;
2913
2914                 /* type specifiers */
2915 #define MATCH_SPECIFIER(token, specifier, name)                         \
2916                 case token:                                                     \
2917                         if (type_specifiers & specifier) {                           \
2918                                 errorf(HERE, "multiple " name " type specifiers given"); \
2919                         } else {                                                    \
2920                                 type_specifiers |= specifier;                           \
2921                         }                                                           \
2922                         next_token();                                               \
2923                         break
2924
2925                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2926                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2927                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2928                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2929                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2930                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2931                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2932                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2933                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2934                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2935                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2936                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2937                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2938                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2939                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2940                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2941                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2942                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2943
2944                 case T_inline:
2945                         next_token();
2946                         specifiers->is_inline = true;
2947                         break;
2948
2949 #if 0
2950                 case T__forceinline:
2951                         next_token();
2952                         specifiers->modifiers |= DM_FORCEINLINE;
2953                         break;
2954 #endif
2955
2956                 case T_long:
2957                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2958                                 errorf(HERE, "too many long type specifiers given");
2959                         } else if (type_specifiers & SPECIFIER_LONG) {
2960                                 type_specifiers |= SPECIFIER_LONG_LONG;
2961                         } else {
2962                                 type_specifiers |= SPECIFIER_LONG;
2963                         }
2964                         next_token();
2965                         break;
2966
2967 #define CHECK_DOUBLE_TYPE()        \
2968                         if ( type != NULL)     \
2969                                 errorf(HERE, "multiple data types in declaration specifiers");
2970
2971                 case T_struct:
2972                         CHECK_DOUBLE_TYPE();
2973                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2974
2975                         type->compound.compound = parse_compound_type_specifier(true);
2976                         break;
2977                 case T_union:
2978                         CHECK_DOUBLE_TYPE();
2979                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2980                         type->compound.compound = parse_compound_type_specifier(false);
2981                         break;
2982                 case T_enum:
2983                         CHECK_DOUBLE_TYPE();
2984                         type = parse_enum_specifier();
2985                         break;
2986                 case T___typeof__:
2987                         CHECK_DOUBLE_TYPE();
2988                         type = parse_typeof();
2989                         break;
2990                 case T___builtin_va_list:
2991                         CHECK_DOUBLE_TYPE();
2992                         type = duplicate_type(type_valist);
2993                         next_token();
2994                         break;
2995
2996                 case T_IDENTIFIER: {
2997                         /* only parse identifier if we haven't found a type yet */
2998                         if (type != NULL || type_specifiers != 0) {
2999                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3000                                  * declaration, so it doesn't generate errors about expecting '(' or
3001                                  * '{' later on. */
3002                                 switch (look_ahead(1)->type) {
3003                                         STORAGE_CLASSES
3004                                         TYPE_SPECIFIERS
3005                                         case T_const:
3006                                         case T_restrict:
3007                                         case T_volatile:
3008                                         case T_inline:
3009                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3010                                         case T_IDENTIFIER:
3011                                         case '&':
3012                                         case '*':
3013                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3014                                                 next_token();
3015                                                 continue;
3016
3017                                         default:
3018                                                 goto finish_specifiers;
3019                                 }
3020                         }
3021
3022                         type_t *const typedef_type = get_typedef_type(token.symbol);
3023                         if (typedef_type == NULL) {
3024                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3025                                  * declaration, so it doesn't generate 'implicit int' followed by more
3026                                  * errors later on. */
3027                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3028                                 switch (la1_type) {
3029                                         DECLARATION_START
3030                                         case T_IDENTIFIER:
3031                                         case '&':
3032                                         case '*': {
3033                                                 errorf(HERE, "%K does not name a type", &token);
3034
3035                                                 entity_t *entity =
3036                                                         create_error_entity(token.symbol, ENTITY_TYPEDEF);
3037
3038                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3039                                                 type->typedeft.typedefe = &entity->typedefe;
3040
3041                                                 next_token();
3042                                                 saw_error = true;
3043                                                 continue;
3044                                         }
3045
3046                                         default:
3047                                                 goto finish_specifiers;
3048                                 }
3049                         }
3050
3051                         next_token();
3052                         type = typedef_type;
3053                         break;
3054                 }
3055
3056                 /* function specifier */
3057                 default:
3058                         goto finish_specifiers;
3059                 }
3060         }
3061
3062 finish_specifiers:
3063         specifiers->attributes = parse_attributes(specifiers->attributes);
3064
3065         in_gcc_extension = old_gcc_extension;
3066
3067         if (type == NULL || (saw_error && type_specifiers != 0)) {
3068                 atomic_type_kind_t atomic_type;
3069
3070                 /* match valid basic types */
3071                 switch (type_specifiers) {
3072                 case SPECIFIER_VOID:
3073                         atomic_type = ATOMIC_TYPE_VOID;
3074                         break;
3075                 case SPECIFIER_WCHAR_T:
3076                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3077                         break;
3078                 case SPECIFIER_CHAR:
3079                         atomic_type = ATOMIC_TYPE_CHAR;
3080                         break;
3081                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3082                         atomic_type = ATOMIC_TYPE_SCHAR;
3083                         break;
3084                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3085                         atomic_type = ATOMIC_TYPE_UCHAR;
3086                         break;
3087                 case SPECIFIER_SHORT:
3088                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3089                 case SPECIFIER_SHORT | SPECIFIER_INT:
3090                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3091                         atomic_type = ATOMIC_TYPE_SHORT;
3092                         break;
3093                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3094                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3095                         atomic_type = ATOMIC_TYPE_USHORT;
3096                         break;
3097                 case SPECIFIER_INT:
3098                 case SPECIFIER_SIGNED:
3099                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3100                         atomic_type = ATOMIC_TYPE_INT;
3101                         break;
3102                 case SPECIFIER_UNSIGNED:
3103                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3104                         atomic_type = ATOMIC_TYPE_UINT;
3105                         break;
3106                 case SPECIFIER_LONG:
3107                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3108                 case SPECIFIER_LONG | SPECIFIER_INT:
3109                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3110                         atomic_type = ATOMIC_TYPE_LONG;
3111                         break;
3112                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3113                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3114                         atomic_type = ATOMIC_TYPE_ULONG;
3115                         break;
3116
3117                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3118                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3119                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3120                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3121                         | SPECIFIER_INT:
3122                         atomic_type = ATOMIC_TYPE_LONGLONG;
3123                         goto warn_about_long_long;
3124
3125                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3126                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3127                         | SPECIFIER_INT:
3128                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3129 warn_about_long_long:
3130                         if (warning.long_long) {
3131                                 warningf(&specifiers->source_position,
3132                                          "ISO C90 does not support 'long long'");
3133                         }
3134                         break;
3135
3136                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3137                         atomic_type = unsigned_int8_type_kind;
3138                         break;
3139
3140                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3141                         atomic_type = unsigned_int16_type_kind;
3142                         break;
3143
3144                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3145                         atomic_type = unsigned_int32_type_kind;
3146                         break;
3147
3148                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3149                         atomic_type = unsigned_int64_type_kind;
3150                         break;
3151
3152                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3153                         atomic_type = unsigned_int128_type_kind;
3154                         break;
3155
3156                 case SPECIFIER_INT8:
3157                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3158                         atomic_type = int8_type_kind;
3159                         break;
3160
3161                 case SPECIFIER_INT16:
3162                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3163                         atomic_type = int16_type_kind;
3164                         break;
3165
3166                 case SPECIFIER_INT32:
3167                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3168                         atomic_type = int32_type_kind;
3169                         break;
3170
3171                 case SPECIFIER_INT64:
3172                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3173                         atomic_type = int64_type_kind;
3174                         break;
3175
3176                 case SPECIFIER_INT128:
3177                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3178                         atomic_type = int128_type_kind;
3179                         break;
3180
3181                 case SPECIFIER_FLOAT:
3182                         atomic_type = ATOMIC_TYPE_FLOAT;
3183                         break;
3184                 case SPECIFIER_DOUBLE:
3185                         atomic_type = ATOMIC_TYPE_DOUBLE;
3186                         break;
3187                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3188                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3189                         break;
3190                 case SPECIFIER_BOOL:
3191                         atomic_type = ATOMIC_TYPE_BOOL;
3192                         break;
3193                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3194                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3195                         atomic_type = ATOMIC_TYPE_FLOAT;
3196                         break;
3197                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3198                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3199                         atomic_type = ATOMIC_TYPE_DOUBLE;
3200                         break;
3201                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3202                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3203                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3204                         break;
3205                 default:
3206                         /* invalid specifier combination, give an error message */
3207                         if (type_specifiers == 0) {
3208                                 if (saw_error)
3209                                         goto end_error;
3210
3211                                 /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3212                                 if (!(c_mode & _CXX) && !strict_mode) {
3213                                         if (warning.implicit_int) {
3214                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
3215                                         }
3216                                         atomic_type = ATOMIC_TYPE_INT;
3217                                         break;
3218                                 } else {
3219                                         errorf(HERE, "no type specifiers given in declaration");
3220                                 }
3221                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3222                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3223                                 errorf(HERE, "signed and unsigned specifiers given");
3224                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3225                                 errorf(HERE, "only integer types can be signed or unsigned");
3226                         } else {
3227                                 errorf(HERE, "multiple datatypes in declaration");
3228                         }
3229                         goto end_error;
3230                 }
3231
3232                 if (type_specifiers & SPECIFIER_COMPLEX) {
3233                         type                = allocate_type_zero(TYPE_COMPLEX);
3234                         type->complex.akind = atomic_type;
3235                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3236                         type                  = allocate_type_zero(TYPE_IMAGINARY);
3237                         type->imaginary.akind = atomic_type;
3238                 } else {
3239                         type                 = allocate_type_zero(TYPE_ATOMIC);
3240                         type->atomic.akind   = atomic_type;
3241                 }
3242                 newtype = true;
3243         } else if (type_specifiers != 0) {
3244                 errorf(HERE, "multiple datatypes in declaration");
3245         }
3246
3247         /* FIXME: check type qualifiers here */
3248         type->base.qualifiers = qualifiers;
3249
3250         if (newtype) {
3251                 type = identify_new_type(type);
3252         } else {
3253                 type = typehash_insert(type);
3254         }
3255
3256         if (specifiers->attributes != NULL)
3257                 type = handle_type_attributes(specifiers->attributes, type);
3258         specifiers->type = type;
3259         return;
3260
3261 end_error:
3262         specifiers->type = type_error_type;
3263 }
3264
3265 static type_qualifiers_t parse_type_qualifiers(void)
3266 {
3267         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3268
3269         while (true) {
3270                 switch (token.type) {
3271                 /* type qualifiers */
3272                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3273                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3274                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3275                 /* microsoft extended type modifiers */
3276                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3277                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3278                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3279                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3280                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3281
3282                 default:
3283                         return qualifiers;
3284                 }
3285         }
3286 }
3287
3288 /**
3289  * Parses an K&R identifier list
3290  */
3291 static void parse_identifier_list(scope_t *scope)
3292 {
3293         do {
3294                 entity_t *entity = allocate_entity_zero(ENTITY_PARAMETER);
3295                 entity->base.source_position = token.source_position;
3296                 entity->base.namespc         = NAMESPACE_NORMAL;
3297                 entity->base.symbol          = token.symbol;
3298                 /* a K&R parameter has no type, yet */
3299                 next_token();
3300
3301                 if (scope != NULL)
3302                         append_entity(scope, entity);
3303         } while (next_if(',') && token.type == T_IDENTIFIER);
3304 }
3305
3306 static entity_t *parse_parameter(void)
3307 {
3308         declaration_specifiers_t specifiers;
3309         memset(&specifiers, 0, sizeof(specifiers));
3310
3311         parse_declaration_specifiers(&specifiers);
3312
3313         entity_t *entity = parse_declarator(&specifiers,
3314                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3315         anonymous_entity = NULL;
3316         return entity;
3317 }
3318
3319 static void semantic_parameter_incomplete(const entity_t *entity)
3320 {
3321         assert(entity->kind == ENTITY_PARAMETER);
3322
3323         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3324          *             list in a function declarator that is part of a
3325          *             definition of that function shall not have
3326          *             incomplete type. */
3327         type_t *type = skip_typeref(entity->declaration.type);
3328         if (is_type_incomplete(type)) {
3329                 errorf(&entity->base.source_position,
3330                                 "parameter '%#T' has incomplete type",
3331                                 entity->declaration.type, entity->base.symbol);
3332         }
3333 }
3334
3335 static bool has_parameters(void)
3336 {
3337         /* func(void) is not a parameter */
3338         if (token.type == T_IDENTIFIER) {
3339                 entity_t const *const entity = get_entity(token.symbol, NAMESPACE_NORMAL);
3340                 if (entity == NULL)
3341                         return true;
3342                 if (entity->kind != ENTITY_TYPEDEF)
3343                         return true;
3344                 if (skip_typeref(entity->typedefe.type) != type_void)
3345                         return true;
3346         } else if (token.type != T_void) {
3347                 return true;
3348         }
3349         if (look_ahead(1)->type != ')')
3350                 return true;
3351         next_token();
3352         return false;
3353 }
3354
3355 /**
3356  * Parses function type parameters (and optionally creates variable_t entities
3357  * for them in a scope)
3358  */
3359 static void parse_parameters(function_type_t *type, scope_t *scope)
3360 {
3361         eat('(');
3362         add_anchor_token(')');
3363         int saved_comma_state = save_and_reset_anchor_state(',');
3364
3365         if (token.type == T_IDENTIFIER &&
3366             !is_typedef_symbol(token.symbol)) {
3367                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
3368                 if (la1_type == ',' || la1_type == ')') {
3369                         type->kr_style_parameters = true;
3370                         parse_identifier_list(scope);
3371                         goto parameters_finished;
3372                 }
3373         }
3374
3375         if (token.type == ')') {
3376                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3377                 if (!(c_mode & _CXX))
3378                         type->unspecified_parameters = true;
3379         } else if (has_parameters()) {
3380                 function_parameter_t **anchor = &type->parameters;
3381                 do {
3382                         switch (token.type) {
3383                         case T_DOTDOTDOT:
3384                                 next_token();
3385                                 type->variadic = true;
3386                                 goto parameters_finished;
3387
3388                         case T_IDENTIFIER:
3389                         case T___extension__:
3390                         DECLARATION_START
3391                         {
3392                                 entity_t *entity = parse_parameter();
3393                                 if (entity->kind == ENTITY_TYPEDEF) {
3394                                         errorf(&entity->base.source_position,
3395                                                         "typedef not allowed as function parameter");
3396                                         break;
3397                                 }
3398                                 assert(is_declaration(entity));
3399
3400                                 semantic_parameter_incomplete(entity);
3401
3402                                 function_parameter_t *const parameter =
3403                                         allocate_parameter(entity->declaration.type);
3404
3405                                 if (scope != NULL) {
3406                                         append_entity(scope, entity);
3407                                 }
3408
3409                                 *anchor = parameter;
3410                                 anchor  = &parameter->next;
3411                                 break;
3412                         }
3413
3414                         default:
3415                                 goto parameters_finished;
3416                         }
3417                 } while (next_if(','));
3418         }
3419
3420 parameters_finished:
3421         rem_anchor_token(')');
3422         expect(')', end_error);
3423
3424 end_error:
3425         restore_anchor_state(',', saved_comma_state);
3426 }
3427
3428 typedef enum construct_type_kind_t {
3429         CONSTRUCT_INVALID,
3430         CONSTRUCT_POINTER,
3431         CONSTRUCT_REFERENCE,
3432         CONSTRUCT_FUNCTION,
3433         CONSTRUCT_ARRAY
3434 } construct_type_kind_t;
3435
3436 typedef union construct_type_t construct_type_t;
3437
3438 typedef struct construct_type_base_t {
3439         construct_type_kind_t  kind;
3440         source_position_t      pos;
3441         construct_type_t      *next;
3442 } construct_type_base_t;
3443
3444 typedef struct parsed_pointer_t {
3445         construct_type_base_t  base;
3446         type_qualifiers_t      type_qualifiers;
3447         variable_t            *base_variable;  /**< MS __based extension. */
3448 } parsed_pointer_t;
3449
3450 typedef struct parsed_reference_t {
3451         construct_type_base_t base;
3452 } parsed_reference_t;
3453
3454 typedef struct construct_function_type_t {
3455         construct_type_base_t  base;
3456         type_t                *function_type;
3457 } construct_function_type_t;
3458
3459 typedef struct parsed_array_t {
3460         construct_type_base_t  base;
3461         type_qualifiers_t      type_qualifiers;
3462         bool                   is_static;
3463         bool                   is_variable;
3464         expression_t          *size;
3465 } parsed_array_t;
3466
3467 union construct_type_t {
3468         construct_type_kind_t     kind;
3469         construct_type_base_t     base;
3470         parsed_pointer_t          pointer;
3471         parsed_reference_t        reference;
3472         construct_function_type_t function;
3473         parsed_array_t            array;
3474 };
3475
3476 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3477 {
3478         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3479         memset(cons, 0, size);
3480         cons->kind     = kind;
3481         cons->base.pos = *HERE;
3482         return cons;
3483 }
3484
3485 /* §6.7.5.1 */
3486 static construct_type_t *parse_pointer_declarator(void)
3487 {
3488         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3489         eat('*');
3490         cons->pointer.type_qualifiers = parse_type_qualifiers();
3491         //cons->pointer.base_variable   = base_variable;
3492
3493         return cons;
3494 }
3495
3496 /* ISO/IEC 14882:1998(E) §8.3.2 */
3497 static construct_type_t *parse_reference_declarator(void)
3498 {
3499         if (!(c_mode & _CXX))
3500                 errorf(HERE, "references are only available for C++");
3501
3502         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3503         eat('&');
3504
3505         return cons;
3506 }
3507
3508 /* §6.7.5.2 */
3509 static construct_type_t *parse_array_declarator(void)
3510 {
3511         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3512         parsed_array_t   *const array = &cons->array;
3513
3514         eat('[');
3515         add_anchor_token(']');
3516
3517         bool is_static = next_if(T_static);
3518
3519         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3520
3521         if (!is_static)
3522                 is_static = next_if(T_static);
3523
3524         array->type_qualifiers = type_qualifiers;
3525         array->is_static       = is_static;
3526
3527         expression_t *size = NULL;
3528         if (token.type == '*' && look_ahead(1)->type == ']') {
3529                 array->is_variable = true;
3530                 next_token();
3531         } else if (token.type != ']') {
3532                 size = parse_assignment_expression();
3533
3534                 /* §6.7.5.2:1  Array size must have integer type */
3535                 type_t *const orig_type = size->base.type;
3536                 type_t *const type      = skip_typeref(orig_type);
3537                 if (!is_type_integer(type) && is_type_valid(type)) {
3538                         errorf(&size->base.source_position,
3539                                "array size '%E' must have integer type but has type '%T'",
3540                                size, orig_type);
3541                 }
3542
3543                 array->size = size;
3544                 mark_vars_read(size, NULL);
3545         }
3546
3547         if (is_static && size == NULL)
3548                 errorf(HERE, "static array parameters require a size");
3549
3550         rem_anchor_token(']');
3551         expect(']', end_error);
3552
3553 end_error:
3554         return cons;
3555 }
3556
3557 /* §6.7.5.3 */
3558 static construct_type_t *parse_function_declarator(scope_t *scope)
3559 {
3560         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3561
3562         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3563         function_type_t *ftype = &type->function;
3564
3565         ftype->linkage            = current_linkage;
3566         ftype->calling_convention = CC_DEFAULT;
3567
3568         parse_parameters(ftype, scope);
3569
3570         cons->function.function_type = type;
3571
3572         return cons;
3573 }
3574
3575 typedef struct parse_declarator_env_t {
3576         bool               may_be_abstract : 1;
3577         bool               must_be_abstract : 1;
3578         decl_modifiers_t   modifiers;
3579         symbol_t          *symbol;
3580         source_position_t  source_position;
3581         scope_t            parameters;
3582         attribute_t       *attributes;
3583 } parse_declarator_env_t;
3584
3585 /* §6.7.5 */
3586 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3587 {
3588         /* construct a single linked list of construct_type_t's which describe
3589          * how to construct the final declarator type */
3590         construct_type_t  *first      = NULL;
3591         construct_type_t **anchor     = &first;
3592
3593         env->attributes = parse_attributes(env->attributes);
3594
3595         for (;;) {
3596                 construct_type_t *type;
3597                 //variable_t       *based = NULL; /* MS __based extension */
3598                 switch (token.type) {
3599                         case '&':
3600                                 type = parse_reference_declarator();
3601                                 break;
3602
3603                         case T__based: {
3604                                 panic("based not supported anymore");
3605                                 /* FALLTHROUGH */
3606                         }
3607
3608                         case '*':
3609                                 type = parse_pointer_declarator();
3610                                 break;
3611
3612                         default:
3613                                 goto ptr_operator_end;
3614                 }
3615
3616                 *anchor = type;
3617                 anchor  = &type->base.next;
3618
3619                 /* TODO: find out if this is correct */
3620                 env->attributes = parse_attributes(env->attributes);
3621         }
3622
3623 ptr_operator_end: ;
3624         construct_type_t *inner_types = NULL;
3625
3626         switch (token.type) {
3627         case T_IDENTIFIER:
3628                 if (env->must_be_abstract) {
3629                         errorf(HERE, "no identifier expected in typename");
3630                 } else {
3631                         env->symbol          = token.symbol;
3632                         env->source_position = token.source_position;
3633                 }
3634                 next_token();
3635                 break;
3636
3637         case '(': {
3638                 /* Parenthesized declarator or function declarator? */
3639                 token_t const *const la1 = look_ahead(1);
3640                 switch (la1->type) {
3641                         case T_IDENTIFIER:
3642                                 if (is_typedef_symbol(la1->symbol)) {
3643                         case ')':
3644                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3645                                          * interpreted as ``function with no parameter specification'', rather
3646                                          * than redundant parentheses around the omitted identifier. */
3647                         default:
3648                                         /* Function declarator. */
3649                                         if (!env->may_be_abstract) {
3650                                                 errorf(HERE, "function declarator must have a name");
3651                                                 goto error_out;
3652                                         }
3653                                 } else {
3654                         case '&':
3655                         case '(':
3656                         case '*':
3657                         case '[':
3658                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3659                                         /* Paranthesized declarator. */
3660                                         next_token();
3661                                         add_anchor_token(')');
3662                                         inner_types = parse_inner_declarator(env);
3663                                         if (inner_types != NULL) {
3664                                                 /* All later declarators only modify the return type */
3665                                                 env->must_be_abstract = true;
3666                                         }
3667                                         rem_anchor_token(')');
3668                                         expect(')', end_error);
3669                                 }
3670                                 break;
3671                 }
3672                 break;
3673         }
3674
3675         default:
3676                 if (env->may_be_abstract)
3677                         break;
3678                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3679 error_out:
3680                 eat_until_anchor();
3681                 return NULL;
3682         }
3683
3684         construct_type_t **const p = anchor;
3685
3686         for (;;) {
3687                 construct_type_t *type;
3688                 switch (token.type) {
3689                 case '(': {
3690                         scope_t *scope = NULL;
3691                         if (!env->must_be_abstract) {
3692                                 scope = &env->parameters;
3693                         }
3694
3695                         type = parse_function_declarator(scope);
3696                         break;
3697                 }
3698                 case '[':
3699                         type = parse_array_declarator();
3700                         break;
3701                 default:
3702                         goto declarator_finished;
3703                 }
3704
3705                 /* insert in the middle of the list (at p) */
3706                 type->base.next = *p;
3707                 *p              = type;
3708                 if (anchor == p)
3709                         anchor = &type->base.next;
3710         }
3711
3712 declarator_finished:
3713         /* append inner_types at the end of the list, we don't to set anchor anymore
3714          * as it's not needed anymore */
3715         *anchor = inner_types;
3716
3717         return first;
3718 end_error:
3719         return NULL;
3720 }
3721
3722 static type_t *construct_declarator_type(construct_type_t *construct_list,
3723                                          type_t *type)
3724 {
3725         construct_type_t *iter = construct_list;
3726         for (; iter != NULL; iter = iter->base.next) {
3727                 source_position_t const* const pos = &iter->base.pos;
3728                 switch (iter->kind) {
3729                 case CONSTRUCT_INVALID:
3730                         break;
3731                 case CONSTRUCT_FUNCTION: {
3732                         construct_function_type_t *function      = &iter->function;
3733                         type_t                    *function_type = function->function_type;
3734
3735                         function_type->function.return_type = type;
3736
3737                         type_t *skipped_return_type = skip_typeref(type);
3738                         /* §6.7.5.3:1 */
3739                         if (is_type_function(skipped_return_type)) {
3740                                 errorf(pos, "function returning function is not allowed");
3741                         } else if (is_type_array(skipped_return_type)) {
3742                                 errorf(pos, "function returning array is not allowed");
3743                         } else {
3744                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
3745                                         warningf(pos, "type qualifiers in return type of function type are meaningless");
3746                                 }
3747                         }
3748
3749                         /* The function type was constructed earlier.  Freeing it here will
3750                          * destroy other types. */
3751                         type = typehash_insert(function_type);
3752                         continue;
3753                 }
3754
3755                 case CONSTRUCT_POINTER: {
3756                         if (is_type_reference(skip_typeref(type)))
3757                                 errorf(pos, "cannot declare a pointer to reference");
3758
3759                         parsed_pointer_t *pointer = &iter->pointer;
3760                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3761                         continue;
3762                 }
3763
3764                 case CONSTRUCT_REFERENCE:
3765                         if (is_type_reference(skip_typeref(type)))
3766                                 errorf(pos, "cannot declare a reference to reference");
3767
3768                         type = make_reference_type(type);
3769                         continue;
3770
3771                 case CONSTRUCT_ARRAY: {
3772                         if (is_type_reference(skip_typeref(type)))
3773                                 errorf(pos, "cannot declare an array of references");
3774
3775                         parsed_array_t *array      = &iter->array;
3776                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3777
3778                         expression_t *size_expression = array->size;
3779                         if (size_expression != NULL) {
3780                                 size_expression
3781                                         = create_implicit_cast(size_expression, type_size_t);
3782                         }
3783
3784                         array_type->base.qualifiers       = array->type_qualifiers;
3785                         array_type->array.element_type    = type;
3786                         array_type->array.is_static       = array->is_static;
3787                         array_type->array.is_variable     = array->is_variable;
3788                         array_type->array.size_expression = size_expression;
3789
3790                         if (size_expression != NULL) {
3791                                 switch (is_constant_expression(size_expression)) {
3792                                         case EXPR_CLASS_CONSTANT: {
3793                                                 long const size = fold_constant_to_int(size_expression);
3794                                                 array_type->array.size          = size;
3795                                                 array_type->array.size_constant = true;
3796                                                 /* §6.7.5.2:1  If the expression is a constant expression, it shall
3797                                                  * have a value greater than zero. */
3798                                                 if (size <= 0) {
3799                                                         if (size < 0 || !GNU_MODE) {
3800                                                                 errorf(&size_expression->base.source_position,
3801                                                                                 "size of array must be greater than zero");
3802                                                         } else if (warning.other) {
3803                                                                 warningf(&size_expression->base.source_position,
3804                                                                                 "zero length arrays are a GCC extension");
3805                                                         }
3806                                                 }
3807                                                 break;
3808                                         }
3809
3810                                         case EXPR_CLASS_VARIABLE:
3811                                                 array_type->array.is_vla = true;
3812                                                 break;
3813
3814                                         case EXPR_CLASS_ERROR:
3815                                                 break;
3816                                 }
3817                         }
3818
3819                         type_t *skipped_type = skip_typeref(type);
3820                         /* §6.7.5.2:1 */
3821                         if (is_type_incomplete(skipped_type)) {
3822                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3823                         } else if (is_type_function(skipped_type)) {
3824                                 errorf(pos, "array of functions is not allowed");
3825                         }
3826                         type = identify_new_type(array_type);
3827                         continue;
3828                 }
3829                 }
3830                 internal_errorf(pos, "invalid type construction found");
3831         }
3832
3833         return type;
3834 }
3835
3836 static type_t *automatic_type_conversion(type_t *orig_type);
3837
3838 static type_t *semantic_parameter(const source_position_t *pos,
3839                                   type_t *type,
3840                                   const declaration_specifiers_t *specifiers,
3841                                   symbol_t *symbol)
3842 {
3843         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3844          *             shall be adjusted to ``qualified pointer to type'',
3845          *             [...]
3846          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3847          *             type'' shall be adjusted to ``pointer to function
3848          *             returning type'', as in 6.3.2.1. */
3849         type = automatic_type_conversion(type);
3850
3851         if (specifiers->is_inline && is_type_valid(type)) {
3852                 errorf(pos, "parameter '%#T' declared 'inline'", type, symbol);
3853         }
3854
3855         /* §6.9.1:6  The declarations in the declaration list shall contain
3856          *           no storage-class specifier other than register and no
3857          *           initializations. */
3858         if (specifiers->thread_local || (
3859                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3860                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3861            ) {
3862                 errorf(pos, "invalid storage class for parameter '%#T'", type, symbol);
3863         }
3864
3865         /* delay test for incomplete type, because we might have (void)
3866          * which is legal but incomplete... */
3867
3868         return type;
3869 }
3870
3871 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3872                                   declarator_flags_t flags)
3873 {
3874         parse_declarator_env_t env;
3875         memset(&env, 0, sizeof(env));
3876         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3877
3878         construct_type_t *construct_type = parse_inner_declarator(&env);
3879         type_t           *orig_type      =
3880                 construct_declarator_type(construct_type, specifiers->type);
3881         type_t           *type           = skip_typeref(orig_type);
3882
3883         if (construct_type != NULL) {
3884                 obstack_free(&temp_obst, construct_type);
3885         }
3886
3887         attribute_t *attributes = parse_attributes(env.attributes);
3888         /* append (shared) specifier attribute behind attributes of this
3889          * declarator */
3890         attribute_t **anchor = &attributes;
3891         while (*anchor != NULL)
3892                 anchor = &(*anchor)->next;
3893         *anchor = specifiers->attributes;
3894
3895         entity_t *entity;
3896         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3897                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
3898                 entity->base.namespc         = NAMESPACE_NORMAL;
3899                 entity->base.symbol          = env.symbol;
3900                 entity->base.source_position = env.source_position;
3901                 entity->typedefe.type        = orig_type;
3902
3903                 if (anonymous_entity != NULL) {
3904                         if (is_type_compound(type)) {
3905                                 assert(anonymous_entity->compound.alias == NULL);
3906                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3907                                        anonymous_entity->kind == ENTITY_UNION);
3908                                 anonymous_entity->compound.alias = entity;
3909                                 anonymous_entity = NULL;
3910                         } else if (is_type_enum(type)) {
3911                                 assert(anonymous_entity->enume.alias == NULL);
3912                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3913                                 anonymous_entity->enume.alias = entity;
3914                                 anonymous_entity = NULL;
3915                         }
3916                 }
3917         } else {
3918                 /* create a declaration type entity */
3919                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3920                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
3921
3922                         if (env.symbol != NULL) {
3923                                 if (specifiers->is_inline && is_type_valid(type)) {
3924                                         errorf(&env.source_position,
3925                                                         "compound member '%Y' declared 'inline'", env.symbol);
3926                                 }
3927
3928                                 if (specifiers->thread_local ||
3929                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3930                                         errorf(&env.source_position,
3931                                                         "compound member '%Y' must have no storage class",
3932                                                         env.symbol);
3933                                 }
3934                         }
3935                 } else if (flags & DECL_IS_PARAMETER) {
3936                         orig_type = semantic_parameter(&env.source_position, orig_type,
3937                                                        specifiers, env.symbol);
3938
3939                         entity = allocate_entity_zero(ENTITY_PARAMETER);
3940                 } else if (is_type_function(type)) {
3941                         entity = allocate_entity_zero(ENTITY_FUNCTION);
3942
3943                         entity->function.is_inline  = specifiers->is_inline;
3944                         entity->function.parameters = env.parameters;
3945
3946                         if (env.symbol != NULL) {
3947                                 /* this needs fixes for C++ */
3948                                 bool in_function_scope = current_function != NULL;
3949
3950                                 if (specifiers->thread_local || (
3951                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3952                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3953                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3954                                                 )) {
3955                                         errorf(&env.source_position,
3956                                                         "invalid storage class for function '%Y'", env.symbol);
3957                                 }
3958                         }
3959                 } else {
3960                         entity = allocate_entity_zero(ENTITY_VARIABLE);
3961
3962                         entity->variable.thread_local = specifiers->thread_local;
3963
3964                         if (env.symbol != NULL) {
3965                                 if (specifiers->is_inline && is_type_valid(type)) {
3966                                         errorf(&env.source_position,
3967                                                         "variable '%Y' declared 'inline'", env.symbol);
3968                                 }
3969
3970                                 bool invalid_storage_class = false;
3971                                 if (current_scope == file_scope) {
3972                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3973                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3974                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3975                                                 invalid_storage_class = true;
3976                                         }
3977                                 } else {
3978                                         if (specifiers->thread_local &&
3979                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3980                                                 invalid_storage_class = true;
3981                                         }
3982                                 }
3983                                 if (invalid_storage_class) {
3984                                         errorf(&env.source_position,
3985                                                         "invalid storage class for variable '%Y'", env.symbol);
3986                                 }
3987                         }
3988                 }
3989
3990                 if (env.symbol != NULL) {
3991                         entity->base.symbol          = env.symbol;
3992                         entity->base.source_position = env.source_position;
3993                 } else {
3994                         entity->base.source_position = specifiers->source_position;
3995                 }
3996                 entity->base.namespc           = NAMESPACE_NORMAL;
3997                 entity->declaration.type       = orig_type;
3998                 entity->declaration.alignment  = get_type_alignment(orig_type);
3999                 entity->declaration.modifiers  = env.modifiers;
4000                 entity->declaration.attributes = attributes;
4001
4002                 storage_class_t storage_class = specifiers->storage_class;
4003                 entity->declaration.declared_storage_class = storage_class;
4004
4005                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
4006                         storage_class = STORAGE_CLASS_AUTO;
4007                 entity->declaration.storage_class = storage_class;
4008         }
4009
4010         if (attributes != NULL) {
4011                 handle_entity_attributes(attributes, entity);
4012         }
4013
4014         return entity;
4015 }
4016
4017 static type_t *parse_abstract_declarator(type_t *base_type)
4018 {
4019         parse_declarator_env_t env;
4020         memset(&env, 0, sizeof(env));
4021         env.may_be_abstract = true;
4022         env.must_be_abstract = true;
4023
4024         construct_type_t *construct_type = parse_inner_declarator(&env);
4025
4026         type_t *result = construct_declarator_type(construct_type, base_type);
4027         if (construct_type != NULL) {
4028                 obstack_free(&temp_obst, construct_type);
4029         }
4030         result = handle_type_attributes(env.attributes, result);
4031
4032         return result;
4033 }
4034
4035 /**
4036  * Check if the declaration of main is suspicious.  main should be a
4037  * function with external linkage, returning int, taking either zero
4038  * arguments, two, or three arguments of appropriate types, ie.
4039  *
4040  * int main([ int argc, char **argv [, char **env ] ]).
4041  *
4042  * @param decl    the declaration to check
4043  * @param type    the function type of the declaration
4044  */
4045 static void check_main(const entity_t *entity)
4046 {
4047         const source_position_t *pos = &entity->base.source_position;
4048         if (entity->kind != ENTITY_FUNCTION) {
4049                 warningf(pos, "'main' is not a function");
4050                 return;
4051         }
4052
4053         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4054                 warningf(pos, "'main' is normally a non-static function");
4055         }
4056
4057         type_t *type = skip_typeref(entity->declaration.type);
4058         assert(is_type_function(type));
4059
4060         function_type_t *func_type = &type->function;
4061         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4062                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4063                          func_type->return_type);
4064         }
4065         const function_parameter_t *parm = func_type->parameters;
4066         if (parm != NULL) {
4067                 type_t *const first_type        = skip_typeref(parm->type);
4068                 type_t *const first_type_unqual = get_unqualified_type(first_type);
4069                 if (!types_compatible(first_type_unqual, type_int)) {
4070                         warningf(pos,
4071                                  "first argument of 'main' should be 'int', but is '%T'",
4072                                  parm->type);
4073                 }
4074                 parm = parm->next;
4075                 if (parm != NULL) {
4076                         type_t *const second_type = skip_typeref(parm->type);
4077                         type_t *const second_type_unqual
4078                                 = get_unqualified_type(second_type);
4079                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
4080                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'",
4081                                          parm->type);
4082                         }
4083                         parm = parm->next;
4084                         if (parm != NULL) {
4085                                 type_t *const third_type = skip_typeref(parm->type);
4086                                 type_t *const third_type_unqual
4087                                         = get_unqualified_type(third_type);
4088                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
4089                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'",
4090                                                  parm->type);
4091                                 }
4092                                 parm = parm->next;
4093                                 if (parm != NULL)
4094                                         goto warn_arg_count;
4095                         }
4096                 } else {
4097 warn_arg_count:
4098                         warningf(pos, "'main' takes only zero, two or three arguments");
4099                 }
4100         }
4101 }
4102
4103 /**
4104  * Check if a symbol is the equal to "main".
4105  */
4106 static bool is_sym_main(const symbol_t *const sym)
4107 {
4108         return strcmp(sym->string, "main") == 0;
4109 }
4110
4111 static void error_redefined_as_different_kind(const source_position_t *pos,
4112                 const entity_t *old, entity_kind_t new_kind)
4113 {
4114         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4115                get_entity_kind_name(old->kind), old->base.symbol,
4116                get_entity_kind_name(new_kind), &old->base.source_position);
4117 }
4118
4119 static bool is_entity_valid(entity_t *const ent)
4120 {
4121         if (is_declaration(ent)) {
4122                 return is_type_valid(skip_typeref(ent->declaration.type));
4123         } else if (ent->kind == ENTITY_TYPEDEF) {
4124                 return is_type_valid(skip_typeref(ent->typedefe.type));
4125         }
4126         return true;
4127 }
4128
4129 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
4130 {
4131         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
4132                 if (attributes_equal(tattr, attr))
4133                         return true;
4134         }
4135         return false;
4136 }
4137
4138 /**
4139  * test wether new_list contains any attributes not included in old_list
4140  */
4141 static bool has_new_attributes(const attribute_t *old_list,
4142                                const attribute_t *new_list)
4143 {
4144         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
4145                 if (!contains_attribute(old_list, attr))
4146                         return true;
4147         }
4148         return false;
4149 }
4150
4151 /**
4152  * Merge in attributes from an attribute list (probably from a previous
4153  * declaration with the same name). Warning: destroys the old structure
4154  * of the attribute list - don't reuse attributes after this call.
4155  */
4156 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
4157 {
4158         attribute_t *next;
4159         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
4160                 next = attr->next;
4161                 if (contains_attribute(decl->attributes, attr))
4162                         continue;
4163
4164                 /* move attribute to new declarations attributes list */
4165                 attr->next       = decl->attributes;
4166                 decl->attributes = attr;
4167         }
4168 }
4169
4170 /**
4171  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4172  * for various problems that occur for multiple definitions
4173  */
4174 entity_t *record_entity(entity_t *entity, const bool is_definition)
4175 {
4176         const symbol_t *const    symbol  = entity->base.symbol;
4177         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4178         const source_position_t *pos     = &entity->base.source_position;
4179
4180         /* can happen in error cases */
4181         if (symbol == NULL)
4182                 return entity;
4183
4184         entity_t *const previous_entity = get_entity(symbol, namespc);
4185         /* pushing the same entity twice will break the stack structure */
4186         assert(previous_entity != entity);
4187
4188         if (entity->kind == ENTITY_FUNCTION) {
4189                 type_t *const orig_type = entity->declaration.type;
4190                 type_t *const type      = skip_typeref(orig_type);
4191
4192                 assert(is_type_function(type));
4193                 if (type->function.unspecified_parameters &&
4194                                 warning.strict_prototypes &&
4195                                 previous_entity == NULL) {
4196                         warningf(pos, "function declaration '%#T' is not a prototype",
4197                                          orig_type, symbol);
4198                 }
4199
4200                 if (warning.main && current_scope == file_scope
4201                                 && is_sym_main(symbol)) {
4202                         check_main(entity);
4203                 }
4204         }
4205
4206         if (is_declaration(entity) &&
4207                         warning.nested_externs &&
4208                         entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
4209                         current_scope != file_scope) {
4210                 warningf(pos, "nested extern declaration of '%#T'",
4211                          entity->declaration.type, symbol);
4212         }
4213
4214         if (previous_entity != NULL) {
4215                 if (previous_entity->base.parent_scope == &current_function->parameters &&
4216                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
4217                         assert(previous_entity->kind == ENTITY_PARAMETER);
4218                         errorf(pos,
4219                                         "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
4220                                         entity->declaration.type, symbol,
4221                                         previous_entity->declaration.type, symbol,
4222                                         &previous_entity->base.source_position);
4223                         goto finish;
4224                 }
4225
4226                 if (previous_entity->base.parent_scope == current_scope) {
4227                         if (previous_entity->kind != entity->kind) {
4228                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
4229                                         error_redefined_as_different_kind(pos, previous_entity,
4230                                                         entity->kind);
4231                                 }
4232                                 goto finish;
4233                         }
4234                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4235                                 errorf(pos, "redeclaration of enum entry '%Y' (declared %P)",
4236                                                 symbol, &previous_entity->base.source_position);
4237                                 goto finish;
4238                         }
4239                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4240                                 /* TODO: C++ allows this for exactly the same type */
4241                                 errorf(pos, "redefinition of typedef '%Y' (declared %P)",
4242                                                 symbol, &previous_entity->base.source_position);
4243                                 goto finish;
4244                         }
4245
4246                         /* at this point we should have only VARIABLES or FUNCTIONS */
4247                         assert(is_declaration(previous_entity) && is_declaration(entity));
4248
4249                         declaration_t *const prev_decl = &previous_entity->declaration;
4250                         declaration_t *const decl      = &entity->declaration;
4251
4252                         /* can happen for K&R style declarations */
4253                         if (prev_decl->type       == NULL             &&
4254                                         previous_entity->kind == ENTITY_PARAMETER &&
4255                                         entity->kind          == ENTITY_PARAMETER) {
4256                                 prev_decl->type                   = decl->type;
4257                                 prev_decl->storage_class          = decl->storage_class;
4258                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4259                                 prev_decl->modifiers              = decl->modifiers;
4260                                 return previous_entity;
4261                         }
4262
4263                         type_t *const orig_type = decl->type;
4264                         assert(orig_type != NULL);
4265                         type_t *const type      = skip_typeref(orig_type);
4266                         type_t *const prev_type = skip_typeref(prev_decl->type);
4267
4268                         if (!types_compatible(type, prev_type)) {
4269                                 errorf(pos,
4270                                                 "declaration '%#T' is incompatible with '%#T' (declared %P)",
4271                                                 orig_type, symbol, prev_decl->type, symbol,
4272                                                 &previous_entity->base.source_position);
4273                         } else {
4274                                 unsigned old_storage_class = prev_decl->storage_class;
4275
4276                                 if (warning.redundant_decls               &&
4277                                                 is_definition                     &&
4278                                                 !prev_decl->used                  &&
4279                                                 !(prev_decl->modifiers & DM_USED) &&
4280                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4281                                         warningf(&previous_entity->base.source_position,
4282                                                         "unnecessary static forward declaration for '%#T'",
4283                                                         prev_decl->type, symbol);
4284                                 }
4285
4286                                 storage_class_t new_storage_class = decl->storage_class;
4287
4288                                 /* pretend no storage class means extern for function
4289                                  * declarations (except if the previous declaration is neither
4290                                  * none nor extern) */
4291                                 if (entity->kind == ENTITY_FUNCTION) {
4292                                         /* the previous declaration could have unspecified parameters or
4293                                          * be a typedef, so use the new type */
4294                                         if (prev_type->function.unspecified_parameters || is_definition)
4295                                                 prev_decl->type = type;
4296
4297                                         switch (old_storage_class) {
4298                                                 case STORAGE_CLASS_NONE:
4299                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4300                                                         /* FALLTHROUGH */
4301
4302                                                 case STORAGE_CLASS_EXTERN:
4303                                                         if (is_definition) {
4304                                                                 if (warning.missing_prototypes &&
4305                                                                                 prev_type->function.unspecified_parameters &&
4306                                                                                 !is_sym_main(symbol)) {
4307                                                                         warningf(pos, "no previous prototype for '%#T'",
4308                                                                                         orig_type, symbol);
4309                                                                 }
4310                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4311                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4312                                                         }
4313                                                         break;
4314
4315                                                 default:
4316                                                         break;
4317                                         }
4318                                 } else if (is_type_incomplete(prev_type)) {
4319                                         prev_decl->type = type;
4320                                 }
4321
4322                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4323                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4324
4325 warn_redundant_declaration: ;
4326                                         bool has_new_attrs
4327                                                 = has_new_attributes(prev_decl->attributes,
4328                                                                      decl->attributes);
4329                                         if (has_new_attrs) {
4330                                                 merge_in_attributes(decl, prev_decl->attributes);
4331                                         } else if (!is_definition        &&
4332                                                         warning.redundant_decls  &&
4333                                                         is_type_valid(prev_type) &&
4334                                                         strcmp(previous_entity->base.source_position.input_name,
4335                                                                 "<builtin>") != 0) {
4336                                                 warningf(pos,
4337                                                          "redundant declaration for '%Y' (declared %P)",
4338                                                          symbol, &previous_entity->base.source_position);
4339                                         }
4340                                 } else if (current_function == NULL) {
4341                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4342                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4343                                                 errorf(pos,
4344                                                        "static declaration of '%Y' follows non-static declaration (declared %P)",
4345                                                        symbol, &previous_entity->base.source_position);
4346                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4347                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4348                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4349                                         } else {
4350                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4351                                                 if (c_mode & _CXX)
4352                                                         goto error_redeclaration;
4353                                                 goto warn_redundant_declaration;
4354                                         }
4355                                 } else if (is_type_valid(prev_type)) {
4356                                         if (old_storage_class == new_storage_class) {
4357 error_redeclaration:
4358                                                 errorf(pos, "redeclaration of '%Y' (declared %P)",
4359                                                                 symbol, &previous_entity->base.source_position);
4360                                         } else {
4361                                                 errorf(pos,
4362                                                                 "redeclaration of '%Y' with different linkage (declared %P)",
4363                                                                 symbol, &previous_entity->base.source_position);
4364                                         }
4365                                 }
4366                         }
4367
4368                         prev_decl->modifiers |= decl->modifiers;
4369                         if (entity->kind == ENTITY_FUNCTION) {
4370                                 previous_entity->function.is_inline |= entity->function.is_inline;
4371                         }
4372                         return previous_entity;
4373                 }
4374
4375                 if (warning.shadow) {
4376                         warningf(pos, "%s '%Y' shadows %s (declared %P)",
4377                                         get_entity_kind_name(entity->kind), symbol,
4378                                         get_entity_kind_name(previous_entity->kind),
4379                                         &previous_entity->base.source_position);
4380                 }
4381         }
4382
4383         if (entity->kind == ENTITY_FUNCTION) {
4384                 if (is_definition &&
4385                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
4386                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
4387                                 warningf(pos, "no previous prototype for '%#T'",
4388                                          entity->declaration.type, symbol);
4389                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
4390                                 warningf(pos, "no previous declaration for '%#T'",
4391                                          entity->declaration.type, symbol);
4392                         }
4393                 }
4394         } else if (warning.missing_declarations &&
4395                         entity->kind == ENTITY_VARIABLE &&
4396                         current_scope == file_scope) {
4397                 declaration_t *declaration = &entity->declaration;
4398                 if (declaration->storage_class == STORAGE_CLASS_NONE) {
4399                         warningf(pos, "no previous declaration for '%#T'",
4400                                  declaration->type, symbol);
4401                 }
4402         }
4403
4404 finish:
4405         assert(entity->base.parent_scope == NULL);
4406         assert(current_scope != NULL);
4407
4408         entity->base.parent_scope = current_scope;
4409         entity->base.namespc      = NAMESPACE_NORMAL;
4410         environment_push(entity);
4411         append_entity(current_scope, entity);
4412
4413         return entity;
4414 }
4415
4416 static void parser_error_multiple_definition(entity_t *entity,
4417                 const source_position_t *source_position)
4418 {
4419         errorf(source_position, "multiple definition of '%Y' (declared %P)",
4420                entity->base.symbol, &entity->base.source_position);
4421 }
4422
4423 static bool is_declaration_specifier(const token_t *token,
4424                                      bool only_specifiers_qualifiers)
4425 {
4426         switch (token->type) {
4427                 TYPE_SPECIFIERS
4428                 TYPE_QUALIFIERS
4429                         return true;
4430                 case T_IDENTIFIER:
4431                         return is_typedef_symbol(token->symbol);
4432
4433                 case T___extension__:
4434                 STORAGE_CLASSES
4435                         return !only_specifiers_qualifiers;
4436
4437                 default:
4438                         return false;
4439         }
4440 }
4441
4442 static void parse_init_declarator_rest(entity_t *entity)
4443 {
4444         type_t *orig_type = type_error_type;
4445
4446         if (entity->base.kind == ENTITY_TYPEDEF) {
4447                 errorf(&entity->base.source_position,
4448                        "typedef '%Y' is initialized (use __typeof__ instead)",
4449                        entity->base.symbol);
4450         } else {
4451                 assert(is_declaration(entity));
4452                 orig_type = entity->declaration.type;
4453         }
4454         eat('=');
4455
4456         type_t *type = skip_typeref(orig_type);
4457
4458         if (entity->kind == ENTITY_VARIABLE
4459                         && entity->variable.initializer != NULL) {
4460                 parser_error_multiple_definition(entity, HERE);
4461         }
4462
4463         declaration_t *const declaration = &entity->declaration;
4464         bool must_be_constant = false;
4465         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4466             entity->base.parent_scope  == file_scope) {
4467                 must_be_constant = true;
4468         }
4469
4470         if (is_type_function(type)) {
4471                 errorf(&entity->base.source_position,
4472                        "function '%#T' is initialized like a variable",
4473                        orig_type, entity->base.symbol);
4474                 orig_type = type_error_type;
4475         }
4476
4477         parse_initializer_env_t env;
4478         env.type             = orig_type;
4479         env.must_be_constant = must_be_constant;
4480         env.entity           = entity;
4481         current_init_decl    = entity;
4482
4483         initializer_t *initializer = parse_initializer(&env);
4484         current_init_decl = NULL;
4485
4486         if (entity->kind == ENTITY_VARIABLE) {
4487                 /* §6.7.5:22  array initializers for arrays with unknown size
4488                  * determine the array type size */
4489                 declaration->type            = env.type;
4490                 entity->variable.initializer = initializer;
4491         }
4492 }
4493
4494 /* parse rest of a declaration without any declarator */
4495 static void parse_anonymous_declaration_rest(
4496                 const declaration_specifiers_t *specifiers)
4497 {
4498         eat(';');
4499         anonymous_entity = NULL;
4500
4501         if (warning.other) {
4502                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4503                                 specifiers->thread_local) {
4504                         warningf(&specifiers->source_position,
4505                                  "useless storage class in empty declaration");
4506                 }
4507
4508                 type_t *type = specifiers->type;
4509                 switch (type->kind) {
4510                         case TYPE_COMPOUND_STRUCT:
4511                         case TYPE_COMPOUND_UNION: {
4512                                 if (type->compound.compound->base.symbol == NULL) {
4513                                         warningf(&specifiers->source_position,
4514                                                  "unnamed struct/union that defines no instances");
4515                                 }
4516                                 break;
4517                         }
4518
4519                         case TYPE_ENUM:
4520                                 break;
4521
4522                         default:
4523                                 warningf(&specifiers->source_position, "empty declaration");
4524                                 break;
4525                 }
4526         }
4527 }
4528
4529 static void check_variable_type_complete(entity_t *ent)
4530 {
4531         if (ent->kind != ENTITY_VARIABLE)
4532                 return;
4533
4534         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4535          *         type for the object shall be complete [...] */
4536         declaration_t *decl = &ent->declaration;
4537         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4538                         decl->storage_class == STORAGE_CLASS_STATIC)
4539                 return;
4540
4541         type_t *const orig_type = decl->type;
4542         type_t *const type      = skip_typeref(orig_type);
4543         if (!is_type_incomplete(type))
4544                 return;
4545
4546         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4547          * are given length one. */
4548         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4549                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4550                 return;
4551         }
4552
4553         errorf(&ent->base.source_position, "variable '%#T' has incomplete type",
4554                         orig_type, ent->base.symbol);
4555 }
4556
4557
4558 static void parse_declaration_rest(entity_t *ndeclaration,
4559                 const declaration_specifiers_t *specifiers,
4560                 parsed_declaration_func         finished_declaration,
4561                 declarator_flags_t              flags)
4562 {
4563         add_anchor_token(';');
4564         add_anchor_token(',');
4565         while (true) {
4566                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
4567
4568                 if (token.type == '=') {
4569                         parse_init_declarator_rest(entity);
4570                 } else if (entity->kind == ENTITY_VARIABLE) {
4571                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4572                          * [...] where the extern specifier is explicitly used. */
4573                         declaration_t *decl = &entity->declaration;
4574                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
4575                                 type_t *type = decl->type;
4576                                 if (is_type_reference(skip_typeref(type))) {
4577                                         errorf(&entity->base.source_position,
4578                                                         "reference '%#T' must be initialized",
4579                                                         type, entity->base.symbol);
4580                                 }
4581                         }
4582                 }
4583
4584                 check_variable_type_complete(entity);
4585
4586                 if (!next_if(','))
4587                         break;
4588
4589                 add_anchor_token('=');
4590                 ndeclaration = parse_declarator(specifiers, flags);
4591                 rem_anchor_token('=');
4592         }
4593         expect(';', end_error);
4594
4595 end_error:
4596         anonymous_entity = NULL;
4597         rem_anchor_token(';');
4598         rem_anchor_token(',');
4599 }
4600
4601 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4602 {
4603         symbol_t *symbol = entity->base.symbol;
4604         if (symbol == NULL) {
4605                 errorf(HERE, "anonymous declaration not valid as function parameter");
4606                 return entity;
4607         }
4608
4609         assert(entity->base.namespc == NAMESPACE_NORMAL);
4610         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4611         if (previous_entity == NULL
4612                         || previous_entity->base.parent_scope != current_scope) {
4613                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
4614                        symbol);
4615                 return entity;
4616         }
4617
4618         if (is_definition) {
4619                 errorf(HERE, "parameter '%Y' is initialised", entity->base.symbol);
4620         }
4621
4622         return record_entity(entity, false);
4623 }
4624
4625 static void parse_declaration(parsed_declaration_func finished_declaration,
4626                               declarator_flags_t      flags)
4627 {
4628         declaration_specifiers_t specifiers;
4629         memset(&specifiers, 0, sizeof(specifiers));
4630
4631         add_anchor_token(';');
4632         parse_declaration_specifiers(&specifiers);
4633         rem_anchor_token(';');
4634
4635         if (token.type == ';') {
4636                 parse_anonymous_declaration_rest(&specifiers);
4637         } else {
4638                 entity_t *entity = parse_declarator(&specifiers, flags);
4639                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4640         }
4641 }
4642
4643 /* §6.5.2.2:6 */
4644 static type_t *get_default_promoted_type(type_t *orig_type)
4645 {
4646         type_t *result = orig_type;
4647
4648         type_t *type = skip_typeref(orig_type);
4649         if (is_type_integer(type)) {
4650                 result = promote_integer(type);
4651         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4652                 result = type_double;
4653         }
4654
4655         return result;
4656 }
4657
4658 static void parse_kr_declaration_list(entity_t *entity)
4659 {
4660         if (entity->kind != ENTITY_FUNCTION)
4661                 return;
4662
4663         type_t *type = skip_typeref(entity->declaration.type);
4664         assert(is_type_function(type));
4665         if (!type->function.kr_style_parameters)
4666                 return;
4667
4668         add_anchor_token('{');
4669
4670         /* push function parameters */
4671         size_t const  top       = environment_top();
4672         scope_t      *old_scope = scope_push(&entity->function.parameters);
4673
4674         entity_t *parameter = entity->function.parameters.entities;
4675         for ( ; parameter != NULL; parameter = parameter->base.next) {
4676                 assert(parameter->base.parent_scope == NULL);
4677                 parameter->base.parent_scope = current_scope;
4678                 environment_push(parameter);
4679         }
4680
4681         /* parse declaration list */
4682         for (;;) {
4683                 switch (token.type) {
4684                         DECLARATION_START
4685                         case T___extension__:
4686                         /* This covers symbols, which are no type, too, and results in
4687                          * better error messages.  The typical cases are misspelled type
4688                          * names and missing includes. */
4689                         case T_IDENTIFIER:
4690                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4691                                 break;
4692                         default:
4693                                 goto decl_list_end;
4694                 }
4695         }
4696 decl_list_end:
4697
4698         /* pop function parameters */
4699         assert(current_scope == &entity->function.parameters);
4700         scope_pop(old_scope);
4701         environment_pop_to(top);
4702
4703         /* update function type */
4704         type_t *new_type = duplicate_type(type);
4705
4706         function_parameter_t  *parameters = NULL;
4707         function_parameter_t **anchor     = &parameters;
4708
4709         /* did we have an earlier prototype? */
4710         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4711         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4712                 proto_type = NULL;
4713
4714         function_parameter_t *proto_parameter = NULL;
4715         if (proto_type != NULL) {
4716                 type_t *proto_type_type = proto_type->declaration.type;
4717                 proto_parameter         = proto_type_type->function.parameters;
4718                 /* If a K&R function definition has a variadic prototype earlier, then
4719                  * make the function definition variadic, too. This should conform to
4720                  * §6.7.5.3:15 and §6.9.1:8. */
4721                 new_type->function.variadic = proto_type_type->function.variadic;
4722         } else {
4723                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4724                  * prototype */
4725                 new_type->function.unspecified_parameters = true;
4726         }
4727
4728         bool need_incompatible_warning = false;
4729         parameter = entity->function.parameters.entities;
4730         for (; parameter != NULL; parameter = parameter->base.next,
4731                         proto_parameter =
4732                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4733                 if (parameter->kind != ENTITY_PARAMETER)
4734                         continue;
4735
4736                 type_t *parameter_type = parameter->declaration.type;
4737                 if (parameter_type == NULL) {
4738                         if (strict_mode) {
4739                                 errorf(HERE, "no type specified for function parameter '%Y'",
4740                                        parameter->base.symbol);
4741                                 parameter_type = type_error_type;
4742                         } else {
4743                                 if (warning.implicit_int) {
4744                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
4745                                                  parameter->base.symbol);
4746                                 }
4747                                 parameter_type = type_int;
4748                         }
4749                         parameter->declaration.type = parameter_type;
4750                 }
4751
4752                 semantic_parameter_incomplete(parameter);
4753
4754                 /* we need the default promoted types for the function type */
4755                 type_t *not_promoted = parameter_type;
4756                 parameter_type       = get_default_promoted_type(parameter_type);
4757
4758                 /* gcc special: if the type of the prototype matches the unpromoted
4759                  * type don't promote */
4760                 if (!strict_mode && proto_parameter != NULL) {
4761                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4762                         type_t *promo_skip   = skip_typeref(parameter_type);
4763                         type_t *param_skip   = skip_typeref(not_promoted);
4764                         if (!types_compatible(proto_p_type, promo_skip)
4765                                 && types_compatible(proto_p_type, param_skip)) {
4766                                 /* don't promote */
4767                                 need_incompatible_warning = true;
4768                                 parameter_type = not_promoted;
4769                         }
4770                 }
4771                 function_parameter_t *const parameter
4772                         = allocate_parameter(parameter_type);
4773
4774                 *anchor = parameter;
4775                 anchor  = &parameter->next;
4776         }
4777
4778         new_type->function.parameters = parameters;
4779         new_type = identify_new_type(new_type);
4780
4781         if (warning.other && need_incompatible_warning) {
4782                 type_t *proto_type_type = proto_type->declaration.type;
4783                 warningf(HERE,
4784                          "declaration '%#T' is incompatible with '%#T' (declared %P)",
4785                          proto_type_type, proto_type->base.symbol,
4786                          new_type, entity->base.symbol,
4787                          &proto_type->base.source_position);
4788         }
4789
4790         entity->declaration.type = new_type;
4791
4792         rem_anchor_token('{');
4793 }
4794
4795 static bool first_err = true;
4796
4797 /**
4798  * When called with first_err set, prints the name of the current function,
4799  * else does noting.
4800  */
4801 static void print_in_function(void)
4802 {
4803         if (first_err) {
4804                 first_err = false;
4805                 diagnosticf("%s: In function '%Y':\n",
4806                             current_function->base.base.source_position.input_name,
4807                             current_function->base.base.symbol);
4808         }
4809 }
4810
4811 /**
4812  * Check if all labels are defined in the current function.
4813  * Check if all labels are used in the current function.
4814  */
4815 static void check_labels(void)
4816 {
4817         for (const goto_statement_t *goto_statement = goto_first;
4818             goto_statement != NULL;
4819             goto_statement = goto_statement->next) {
4820                 /* skip computed gotos */
4821                 if (goto_statement->expression != NULL)
4822                         continue;
4823
4824                 label_t *label = goto_statement->label;
4825
4826                 label->used = true;
4827                 if (label->base.source_position.input_name == NULL) {
4828                         print_in_function();
4829                         errorf(&goto_statement->base.source_position,
4830                                "label '%Y' used but not defined", label->base.symbol);
4831                  }
4832         }
4833
4834         if (warning.unused_label) {
4835                 for (const label_statement_t *label_statement = label_first;
4836                          label_statement != NULL;
4837                          label_statement = label_statement->next) {
4838                         label_t *label = label_statement->label;
4839
4840                         if (! label->used) {
4841                                 print_in_function();
4842                                 warningf(&label_statement->base.source_position,
4843                                          "label '%Y' defined but not used", label->base.symbol);
4844                         }
4845                 }
4846         }
4847 }
4848
4849 static void warn_unused_entity(entity_t *entity, entity_t *last)
4850 {
4851         entity_t const *const end = last != NULL ? last->base.next : NULL;
4852         for (; entity != end; entity = entity->base.next) {
4853                 if (!is_declaration(entity))
4854                         continue;
4855
4856                 declaration_t *declaration = &entity->declaration;
4857                 if (declaration->implicit)
4858                         continue;
4859
4860                 if (!declaration->used) {
4861                         print_in_function();
4862                         const char *what = get_entity_kind_name(entity->kind);
4863                         warningf(&entity->base.source_position, "%s '%Y' is unused",
4864                                  what, entity->base.symbol);
4865                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4866                         print_in_function();
4867                         const char *what = get_entity_kind_name(entity->kind);
4868                         warningf(&entity->base.source_position, "%s '%Y' is never read",
4869                                  what, entity->base.symbol);
4870                 }
4871         }
4872 }
4873
4874 static void check_unused_variables(statement_t *const stmt, void *const env)
4875 {
4876         (void)env;
4877
4878         switch (stmt->kind) {
4879                 case STATEMENT_DECLARATION: {
4880                         declaration_statement_t const *const decls = &stmt->declaration;
4881                         warn_unused_entity(decls->declarations_begin,
4882                                            decls->declarations_end);
4883                         return;
4884                 }
4885
4886                 case STATEMENT_FOR:
4887                         warn_unused_entity(stmt->fors.scope.entities, NULL);
4888                         return;
4889
4890                 default:
4891                         return;
4892         }
4893 }
4894
4895 /**
4896  * Check declarations of current_function for unused entities.
4897  */
4898 static void check_declarations(void)
4899 {
4900         if (warning.unused_parameter) {
4901                 const scope_t *scope = &current_function->parameters;
4902
4903                 /* do not issue unused warnings for main */
4904                 if (!is_sym_main(current_function->base.base.symbol)) {
4905                         warn_unused_entity(scope->entities, NULL);
4906                 }
4907         }
4908         if (warning.unused_variable) {
4909                 walk_statements(current_function->statement, check_unused_variables,
4910                                 NULL);
4911         }
4912 }
4913
4914 static int determine_truth(expression_t const* const cond)
4915 {
4916         return
4917                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4918                 fold_constant_to_bool(cond)                         ? 1 :
4919                 -1;
4920 }
4921
4922 static void check_reachable(statement_t *);
4923 static bool reaches_end;
4924
4925 static bool expression_returns(expression_t const *const expr)
4926 {
4927         switch (expr->kind) {
4928                 case EXPR_CALL: {
4929                         expression_t const *const func = expr->call.function;
4930                         if (func->kind == EXPR_REFERENCE) {
4931                                 entity_t *entity = func->reference.entity;
4932                                 if (entity->kind == ENTITY_FUNCTION
4933                                                 && entity->declaration.modifiers & DM_NORETURN)
4934                                         return false;
4935                         }
4936
4937                         if (!expression_returns(func))
4938                                 return false;
4939
4940                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4941                                 if (!expression_returns(arg->expression))
4942                                         return false;
4943                         }
4944
4945                         return true;
4946                 }
4947
4948                 case EXPR_REFERENCE:
4949                 case EXPR_REFERENCE_ENUM_VALUE:
4950                 EXPR_LITERAL_CASES
4951                 case EXPR_STRING_LITERAL:
4952                 case EXPR_WIDE_STRING_LITERAL:
4953                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4954                 case EXPR_LABEL_ADDRESS:
4955                 case EXPR_CLASSIFY_TYPE:
4956                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4957                 case EXPR_ALIGNOF:
4958                 case EXPR_FUNCNAME:
4959                 case EXPR_BUILTIN_CONSTANT_P:
4960                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4961                 case EXPR_OFFSETOF:
4962                 case EXPR_INVALID:
4963                         return true;
4964
4965                 case EXPR_STATEMENT: {
4966                         bool old_reaches_end = reaches_end;
4967                         reaches_end = false;
4968                         check_reachable(expr->statement.statement);
4969                         bool returns = reaches_end;
4970                         reaches_end = old_reaches_end;
4971                         return returns;
4972                 }
4973
4974                 case EXPR_CONDITIONAL:
4975                         // TODO handle constant expression
4976
4977                         if (!expression_returns(expr->conditional.condition))
4978                                 return false;
4979
4980                         if (expr->conditional.true_expression != NULL
4981                                         && expression_returns(expr->conditional.true_expression))
4982                                 return true;
4983
4984                         return expression_returns(expr->conditional.false_expression);
4985
4986                 case EXPR_SELECT:
4987                         return expression_returns(expr->select.compound);
4988
4989                 case EXPR_ARRAY_ACCESS:
4990                         return
4991                                 expression_returns(expr->array_access.array_ref) &&
4992                                 expression_returns(expr->array_access.index);
4993
4994                 case EXPR_VA_START:
4995                         return expression_returns(expr->va_starte.ap);
4996
4997                 case EXPR_VA_ARG:
4998                         return expression_returns(expr->va_arge.ap);
4999
5000                 case EXPR_VA_COPY:
5001                         return expression_returns(expr->va_copye.src);
5002
5003                 EXPR_UNARY_CASES_MANDATORY
5004                         return expression_returns(expr->unary.value);
5005
5006                 case EXPR_UNARY_THROW:
5007                         return false;
5008
5009                 EXPR_BINARY_CASES
5010                         // TODO handle constant lhs of && and ||
5011                         return
5012                                 expression_returns(expr->binary.left) &&
5013                                 expression_returns(expr->binary.right);
5014
5015                 case EXPR_UNKNOWN:
5016                         break;
5017         }
5018
5019         panic("unhandled expression");
5020 }
5021
5022 static bool initializer_returns(initializer_t const *const init)
5023 {
5024         switch (init->kind) {
5025                 case INITIALIZER_VALUE:
5026                         return expression_returns(init->value.value);
5027
5028                 case INITIALIZER_LIST: {
5029                         initializer_t * const*       i       = init->list.initializers;
5030                         initializer_t * const* const end     = i + init->list.len;
5031                         bool                         returns = true;
5032                         for (; i != end; ++i) {
5033                                 if (!initializer_returns(*i))
5034                                         returns = false;
5035                         }
5036                         return returns;
5037                 }
5038
5039                 case INITIALIZER_STRING:
5040                 case INITIALIZER_WIDE_STRING:
5041                 case INITIALIZER_DESIGNATOR: // designators have no payload
5042                         return true;
5043         }
5044         panic("unhandled initializer");
5045 }
5046
5047 static bool noreturn_candidate;
5048
5049 static void check_reachable(statement_t *const stmt)
5050 {
5051         if (stmt->base.reachable)
5052                 return;
5053         if (stmt->kind != STATEMENT_DO_WHILE)
5054                 stmt->base.reachable = true;
5055
5056         statement_t *last = stmt;
5057         statement_t *next;
5058         switch (stmt->kind) {
5059                 case STATEMENT_INVALID:
5060                 case STATEMENT_EMPTY:
5061                 case STATEMENT_ASM:
5062                         next = stmt->base.next;
5063                         break;
5064
5065                 case STATEMENT_DECLARATION: {
5066                         declaration_statement_t const *const decl = &stmt->declaration;
5067                         entity_t                const *      ent  = decl->declarations_begin;
5068                         entity_t                const *const last = decl->declarations_end;
5069                         if (ent != NULL) {
5070                                 for (;; ent = ent->base.next) {
5071                                         if (ent->kind                 == ENTITY_VARIABLE &&
5072                                                         ent->variable.initializer != NULL            &&
5073                                                         !initializer_returns(ent->variable.initializer)) {
5074                                                 return;
5075                                         }
5076                                         if (ent == last)
5077                                                 break;
5078                                 }
5079                         }
5080                         next = stmt->base.next;
5081                         break;
5082                 }
5083
5084                 case STATEMENT_COMPOUND:
5085                         next = stmt->compound.statements;
5086                         if (next == NULL)
5087                                 next = stmt->base.next;
5088                         break;
5089
5090                 case STATEMENT_RETURN: {
5091                         expression_t const *const val = stmt->returns.value;
5092                         if (val == NULL || expression_returns(val))
5093                                 noreturn_candidate = false;
5094                         return;
5095                 }
5096
5097                 case STATEMENT_IF: {
5098                         if_statement_t const *const ifs  = &stmt->ifs;
5099                         expression_t   const *const cond = ifs->condition;
5100
5101                         if (!expression_returns(cond))
5102                                 return;
5103
5104                         int const val = determine_truth(cond);
5105
5106                         if (val >= 0)
5107                                 check_reachable(ifs->true_statement);
5108
5109                         if (val > 0)
5110                                 return;
5111
5112                         if (ifs->false_statement != NULL) {
5113                                 check_reachable(ifs->false_statement);
5114                                 return;
5115                         }
5116
5117                         next = stmt->base.next;
5118                         break;
5119                 }
5120
5121                 case STATEMENT_SWITCH: {
5122                         switch_statement_t const *const switchs = &stmt->switchs;
5123                         expression_t       const *const expr    = switchs->expression;
5124
5125                         if (!expression_returns(expr))
5126                                 return;
5127
5128                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
5129                                 long                    const val      = fold_constant_to_int(expr);
5130                                 case_label_statement_t *      defaults = NULL;
5131                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5132                                         if (i->expression == NULL) {
5133                                                 defaults = i;
5134                                                 continue;
5135                                         }
5136
5137                                         if (i->first_case <= val && val <= i->last_case) {
5138                                                 check_reachable((statement_t*)i);
5139                                                 return;
5140                                         }
5141                                 }
5142
5143                                 if (defaults != NULL) {
5144                                         check_reachable((statement_t*)defaults);
5145                                         return;
5146                                 }
5147                         } else {
5148                                 bool has_default = false;
5149                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5150                                         if (i->expression == NULL)
5151                                                 has_default = true;
5152
5153                                         check_reachable((statement_t*)i);
5154                                 }
5155
5156                                 if (has_default)
5157                                         return;
5158                         }
5159
5160                         next = stmt->base.next;
5161                         break;
5162                 }
5163
5164                 case STATEMENT_EXPRESSION: {
5165                         /* Check for noreturn function call */
5166                         expression_t const *const expr = stmt->expression.expression;
5167                         if (!expression_returns(expr))
5168                                 return;
5169
5170                         next = stmt->base.next;
5171                         break;
5172                 }
5173
5174                 case STATEMENT_CONTINUE:
5175                         for (statement_t *parent = stmt;;) {
5176                                 parent = parent->base.parent;
5177                                 if (parent == NULL) /* continue not within loop */
5178                                         return;
5179
5180                                 next = parent;
5181                                 switch (parent->kind) {
5182                                         case STATEMENT_WHILE:    goto continue_while;
5183                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5184                                         case STATEMENT_FOR:      goto continue_for;
5185
5186                                         default: break;
5187                                 }
5188                         }
5189
5190                 case STATEMENT_BREAK:
5191                         for (statement_t *parent = stmt;;) {
5192                                 parent = parent->base.parent;
5193                                 if (parent == NULL) /* break not within loop/switch */
5194                                         return;
5195
5196                                 switch (parent->kind) {
5197                                         case STATEMENT_SWITCH:
5198                                         case STATEMENT_WHILE:
5199                                         case STATEMENT_DO_WHILE:
5200                                         case STATEMENT_FOR:
5201                                                 last = parent;
5202                                                 next = parent->base.next;
5203                                                 goto found_break_parent;
5204
5205                                         default: break;
5206                                 }
5207                         }
5208 found_break_parent:
5209                         break;
5210
5211                 case STATEMENT_GOTO:
5212                         if (stmt->gotos.expression) {
5213                                 if (!expression_returns(stmt->gotos.expression))
5214                                         return;
5215
5216                                 statement_t *parent = stmt->base.parent;
5217                                 if (parent == NULL) /* top level goto */
5218                                         return;
5219                                 next = parent;
5220                         } else {
5221                                 next = stmt->gotos.label->statement;
5222                                 if (next == NULL) /* missing label */
5223                                         return;
5224                         }
5225                         break;
5226
5227                 case STATEMENT_LABEL:
5228                         next = stmt->label.statement;
5229                         break;
5230
5231                 case STATEMENT_CASE_LABEL:
5232                         next = stmt->case_label.statement;
5233                         break;
5234
5235                 case STATEMENT_WHILE: {
5236                         while_statement_t const *const whiles = &stmt->whiles;
5237                         expression_t      const *const cond   = whiles->condition;
5238
5239                         if (!expression_returns(cond))
5240                                 return;
5241
5242                         int const val = determine_truth(cond);
5243
5244                         if (val >= 0)
5245                                 check_reachable(whiles->body);
5246
5247                         if (val > 0)
5248                                 return;
5249
5250                         next = stmt->base.next;
5251                         break;
5252                 }
5253
5254                 case STATEMENT_DO_WHILE:
5255                         next = stmt->do_while.body;
5256                         break;
5257
5258                 case STATEMENT_FOR: {
5259                         for_statement_t *const fors = &stmt->fors;
5260
5261                         if (fors->condition_reachable)
5262                                 return;
5263                         fors->condition_reachable = true;
5264
5265                         expression_t const *const cond = fors->condition;
5266
5267                         int val;
5268                         if (cond == NULL) {
5269                                 val = 1;
5270                         } else if (expression_returns(cond)) {
5271                                 val = determine_truth(cond);
5272                         } else {
5273                                 return;
5274                         }
5275
5276                         if (val >= 0)
5277                                 check_reachable(fors->body);
5278
5279                         if (val > 0)
5280                                 return;
5281
5282                         next = stmt->base.next;
5283                         break;
5284                 }
5285
5286                 case STATEMENT_MS_TRY: {
5287                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5288                         check_reachable(ms_try->try_statement);
5289                         next = ms_try->final_statement;
5290                         break;
5291                 }
5292
5293                 case STATEMENT_LEAVE: {
5294                         statement_t *parent = stmt;
5295                         for (;;) {
5296                                 parent = parent->base.parent;
5297                                 if (parent == NULL) /* __leave not within __try */
5298                                         return;
5299
5300                                 if (parent->kind == STATEMENT_MS_TRY) {
5301                                         last = parent;
5302                                         next = parent->ms_try.final_statement;
5303                                         break;
5304                                 }
5305                         }
5306                         break;
5307                 }
5308
5309                 default:
5310                         panic("invalid statement kind");
5311         }
5312
5313         while (next == NULL) {
5314                 next = last->base.parent;
5315                 if (next == NULL) {
5316                         noreturn_candidate = false;
5317
5318                         type_t *const type = skip_typeref(current_function->base.type);
5319                         assert(is_type_function(type));
5320                         type_t *const ret  = skip_typeref(type->function.return_type);
5321                         if (warning.return_type                    &&
5322                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
5323                             is_type_valid(ret)                     &&
5324                             !is_sym_main(current_function->base.base.symbol)) {
5325                                 warningf(&stmt->base.source_position,
5326                                          "control reaches end of non-void function");
5327                         }
5328                         return;
5329                 }
5330
5331                 switch (next->kind) {
5332                         case STATEMENT_INVALID:
5333                         case STATEMENT_EMPTY:
5334                         case STATEMENT_DECLARATION:
5335                         case STATEMENT_EXPRESSION:
5336                         case STATEMENT_ASM:
5337                         case STATEMENT_RETURN:
5338                         case STATEMENT_CONTINUE:
5339                         case STATEMENT_BREAK:
5340                         case STATEMENT_GOTO:
5341                         case STATEMENT_LEAVE:
5342                                 panic("invalid control flow in function");
5343
5344                         case STATEMENT_COMPOUND:
5345                                 if (next->compound.stmt_expr) {
5346                                         reaches_end = true;
5347                                         return;
5348                                 }
5349                                 /* FALLTHROUGH */
5350                         case STATEMENT_IF:
5351                         case STATEMENT_SWITCH:
5352                         case STATEMENT_LABEL:
5353                         case STATEMENT_CASE_LABEL:
5354                                 last = next;
5355                                 next = next->base.next;
5356                                 break;
5357
5358                         case STATEMENT_WHILE: {
5359 continue_while:
5360                                 if (next->base.reachable)
5361                                         return;
5362                                 next->base.reachable = true;
5363
5364                                 while_statement_t const *const whiles = &next->whiles;
5365                                 expression_t      const *const cond   = whiles->condition;
5366
5367                                 if (!expression_returns(cond))
5368                                         return;
5369
5370                                 int const val = determine_truth(cond);
5371
5372                                 if (val >= 0)
5373                                         check_reachable(whiles->body);
5374
5375                                 if (val > 0)
5376                                         return;
5377
5378                                 last = next;
5379                                 next = next->base.next;
5380                                 break;
5381                         }
5382
5383                         case STATEMENT_DO_WHILE: {
5384 continue_do_while:
5385                                 if (next->base.reachable)
5386                                         return;
5387                                 next->base.reachable = true;
5388
5389                                 do_while_statement_t const *const dw   = &next->do_while;
5390                                 expression_t         const *const cond = dw->condition;
5391
5392                                 if (!expression_returns(cond))
5393                                         return;
5394
5395                                 int const val = determine_truth(cond);
5396
5397                                 if (val >= 0)
5398                                         check_reachable(dw->body);
5399
5400                                 if (val > 0)
5401                                         return;
5402
5403                                 last = next;
5404                                 next = next->base.next;
5405                                 break;
5406                         }
5407
5408                         case STATEMENT_FOR: {
5409 continue_for:;
5410                                 for_statement_t *const fors = &next->fors;
5411
5412                                 fors->step_reachable = true;
5413
5414                                 if (fors->condition_reachable)
5415                                         return;
5416                                 fors->condition_reachable = true;
5417
5418                                 expression_t const *const cond = fors->condition;
5419
5420                                 int val;
5421                                 if (cond == NULL) {
5422                                         val = 1;
5423                                 } else if (expression_returns(cond)) {
5424                                         val = determine_truth(cond);
5425                                 } else {
5426                                         return;
5427                                 }
5428
5429                                 if (val >= 0)
5430                                         check_reachable(fors->body);
5431
5432                                 if (val > 0)
5433                                         return;
5434
5435                                 last = next;
5436                                 next = next->base.next;
5437                                 break;
5438                         }
5439
5440                         case STATEMENT_MS_TRY:
5441                                 last = next;
5442                                 next = next->ms_try.final_statement;
5443                                 break;
5444                 }
5445         }
5446
5447         check_reachable(next);
5448 }
5449
5450 static void check_unreachable(statement_t* const stmt, void *const env)
5451 {
5452         (void)env;
5453
5454         switch (stmt->kind) {
5455                 case STATEMENT_DO_WHILE:
5456                         if (!stmt->base.reachable) {
5457                                 expression_t const *const cond = stmt->do_while.condition;
5458                                 if (determine_truth(cond) >= 0) {
5459                                         warningf(&cond->base.source_position,
5460                                                  "condition of do-while-loop is unreachable");
5461                                 }
5462                         }
5463                         return;
5464
5465                 case STATEMENT_FOR: {
5466                         for_statement_t const* const fors = &stmt->fors;
5467
5468                         // if init and step are unreachable, cond is unreachable, too
5469                         if (!stmt->base.reachable && !fors->step_reachable) {
5470                                 warningf(&stmt->base.source_position, "statement is unreachable");
5471                         } else {
5472                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5473                                         warningf(&fors->initialisation->base.source_position,
5474                                                  "initialisation of for-statement is unreachable");
5475                                 }
5476
5477                                 if (!fors->condition_reachable && fors->condition != NULL) {
5478                                         warningf(&fors->condition->base.source_position,
5479                                                  "condition of for-statement is unreachable");
5480                                 }
5481
5482                                 if (!fors->step_reachable && fors->step != NULL) {
5483                                         warningf(&fors->step->base.source_position,
5484                                                  "step of for-statement is unreachable");
5485                                 }
5486                         }
5487                         return;
5488                 }
5489
5490                 case STATEMENT_COMPOUND:
5491                         if (stmt->compound.statements != NULL)
5492                                 return;
5493                         goto warn_unreachable;
5494
5495                 case STATEMENT_DECLARATION: {
5496                         /* Only warn if there is at least one declarator with an initializer.
5497                          * This typically occurs in switch statements. */
5498                         declaration_statement_t const *const decl = &stmt->declaration;
5499                         entity_t                const *      ent  = decl->declarations_begin;
5500                         entity_t                const *const last = decl->declarations_end;
5501                         if (ent != NULL) {
5502                                 for (;; ent = ent->base.next) {
5503                                         if (ent->kind                 == ENTITY_VARIABLE &&
5504                                                         ent->variable.initializer != NULL) {
5505                                                 goto warn_unreachable;
5506                                         }
5507                                         if (ent == last)
5508                                                 return;
5509                                 }
5510                         }
5511                 }
5512
5513                 default:
5514 warn_unreachable:
5515                         if (!stmt->base.reachable)
5516                                 warningf(&stmt->base.source_position, "statement is unreachable");
5517                         return;
5518         }
5519 }
5520
5521 static void parse_external_declaration(void)
5522 {
5523         /* function-definitions and declarations both start with declaration
5524          * specifiers */
5525         declaration_specifiers_t specifiers;
5526         memset(&specifiers, 0, sizeof(specifiers));
5527
5528         add_anchor_token(';');
5529         parse_declaration_specifiers(&specifiers);
5530         rem_anchor_token(';');
5531
5532         /* must be a declaration */
5533         if (token.type == ';') {
5534                 parse_anonymous_declaration_rest(&specifiers);
5535                 return;
5536         }
5537
5538         add_anchor_token(',');
5539         add_anchor_token('=');
5540         add_anchor_token(';');
5541         add_anchor_token('{');
5542
5543         /* declarator is common to both function-definitions and declarations */
5544         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5545
5546         rem_anchor_token('{');
5547         rem_anchor_token(';');
5548         rem_anchor_token('=');
5549         rem_anchor_token(',');
5550
5551         /* must be a declaration */
5552         switch (token.type) {
5553                 case ',':
5554                 case ';':
5555                 case '=':
5556                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5557                                         DECL_FLAGS_NONE);
5558                         return;
5559         }
5560
5561         /* must be a function definition */
5562         parse_kr_declaration_list(ndeclaration);
5563
5564         if (token.type != '{') {
5565                 parse_error_expected("while parsing function definition", '{', NULL);
5566                 eat_until_matching_token(';');
5567                 return;
5568         }
5569
5570         assert(is_declaration(ndeclaration));
5571         type_t *const orig_type = ndeclaration->declaration.type;
5572         type_t *      type      = skip_typeref(orig_type);
5573
5574         if (!is_type_function(type)) {
5575                 if (is_type_valid(type)) {
5576                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
5577                                type, ndeclaration->base.symbol);
5578                 }
5579                 eat_block();
5580                 return;
5581         } else if (is_typeref(orig_type)) {
5582                 /* §6.9.1:2 */
5583                 errorf(&ndeclaration->base.source_position,
5584                                 "type of function definition '%#T' is a typedef",
5585                                 orig_type, ndeclaration->base.symbol);
5586         }
5587
5588         if (warning.aggregate_return &&
5589             is_type_compound(skip_typeref(type->function.return_type))) {
5590                 warningf(HERE, "function '%Y' returns an aggregate",
5591                          ndeclaration->base.symbol);
5592         }
5593         if (warning.traditional && !type->function.unspecified_parameters) {
5594                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
5595                         ndeclaration->base.symbol);
5596         }
5597         if (warning.old_style_definition && type->function.unspecified_parameters) {
5598                 warningf(HERE, "old-style function definition '%Y'",
5599                         ndeclaration->base.symbol);
5600         }
5601
5602         /* §6.7.5.3:14 a function definition with () means no
5603          * parameters (and not unspecified parameters) */
5604         if (type->function.unspecified_parameters &&
5605                         type->function.parameters == NULL) {
5606                 type_t *copy                          = duplicate_type(type);
5607                 copy->function.unspecified_parameters = false;
5608                 type                                  = identify_new_type(copy);
5609
5610                 ndeclaration->declaration.type = type;
5611         }
5612
5613         entity_t *const entity = record_entity(ndeclaration, true);
5614         assert(entity->kind == ENTITY_FUNCTION);
5615         assert(ndeclaration->kind == ENTITY_FUNCTION);
5616
5617         function_t *const function = &entity->function;
5618         if (ndeclaration != entity) {
5619                 function->parameters = ndeclaration->function.parameters;
5620         }
5621         assert(is_declaration(entity));
5622         type = skip_typeref(entity->declaration.type);
5623
5624         /* push function parameters and switch scope */
5625         size_t const  top       = environment_top();
5626         scope_t      *old_scope = scope_push(&function->parameters);
5627
5628         entity_t *parameter = function->parameters.entities;
5629         for (; parameter != NULL; parameter = parameter->base.next) {
5630                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5631                         parameter->base.parent_scope = current_scope;
5632                 }
5633                 assert(parameter->base.parent_scope == NULL
5634                                 || parameter->base.parent_scope == current_scope);
5635                 parameter->base.parent_scope = current_scope;
5636                 if (parameter->base.symbol == NULL) {
5637                         errorf(&parameter->base.source_position, "parameter name omitted");
5638                         continue;
5639                 }
5640                 environment_push(parameter);
5641         }
5642
5643         if (function->statement != NULL) {
5644                 parser_error_multiple_definition(entity, HERE);
5645                 eat_block();
5646         } else {
5647                 /* parse function body */
5648                 int         label_stack_top      = label_top();
5649                 function_t *old_current_function = current_function;
5650                 entity_t   *old_current_entity   = current_entity;
5651                 current_function                 = function;
5652                 current_entity                   = entity;
5653                 current_parent                   = NULL;
5654
5655                 goto_first   = NULL;
5656                 goto_anchor  = &goto_first;
5657                 label_first  = NULL;
5658                 label_anchor = &label_first;
5659
5660                 statement_t *const body = parse_compound_statement(false);
5661                 function->statement = body;
5662                 first_err = true;
5663                 check_labels();
5664                 check_declarations();
5665                 if (warning.return_type      ||
5666                     warning.unreachable_code ||
5667                     (warning.missing_noreturn
5668                      && !(function->base.modifiers & DM_NORETURN))) {
5669                         noreturn_candidate = true;
5670                         check_reachable(body);
5671                         if (warning.unreachable_code)
5672                                 walk_statements(body, check_unreachable, NULL);
5673                         if (warning.missing_noreturn &&
5674                             noreturn_candidate       &&
5675                             !(function->base.modifiers & DM_NORETURN)) {
5676                                 warningf(&body->base.source_position,
5677                                          "function '%#T' is candidate for attribute 'noreturn'",
5678                                          type, entity->base.symbol);
5679                         }
5680                 }
5681
5682                 assert(current_parent   == NULL);
5683                 assert(current_function == function);
5684                 assert(current_entity   == entity);
5685                 current_entity   = old_current_entity;
5686                 current_function = old_current_function;
5687                 label_pop_to(label_stack_top);
5688         }
5689
5690         assert(current_scope == &function->parameters);
5691         scope_pop(old_scope);
5692         environment_pop_to(top);
5693 }
5694
5695 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
5696                                   source_position_t *source_position,
5697                                   const symbol_t *symbol)
5698 {
5699         type_t *type = allocate_type_zero(TYPE_BITFIELD);
5700
5701         type->bitfield.base_type       = base_type;
5702         type->bitfield.size_expression = size;
5703
5704         il_size_t bit_size;
5705         type_t *skipped_type = skip_typeref(base_type);
5706         if (!is_type_integer(skipped_type)) {
5707                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5708                        base_type);
5709                 bit_size = 0;
5710         } else {
5711                 bit_size = get_type_size(base_type) * 8;
5712         }
5713
5714         if (is_constant_expression(size) == EXPR_CLASS_CONSTANT) {
5715                 long v = fold_constant_to_int(size);
5716                 const symbol_t *user_symbol = symbol == NULL ? sym_anonymous : symbol;
5717
5718                 if (v < 0) {
5719                         errorf(source_position, "negative width in bit-field '%Y'",
5720                                user_symbol);
5721                 } else if (v == 0 && symbol != NULL) {
5722                         errorf(source_position, "zero width for bit-field '%Y'",
5723                                user_symbol);
5724                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
5725                         errorf(source_position, "width of '%Y' exceeds its type",
5726                                user_symbol);
5727                 } else {
5728                         type->bitfield.bit_size = v;
5729                 }
5730         }
5731
5732         return type;
5733 }
5734
5735 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5736 {
5737         entity_t *iter = compound->members.entities;
5738         for (; iter != NULL; iter = iter->base.next) {
5739                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5740                         continue;
5741
5742                 if (iter->base.symbol == symbol) {
5743                         return iter;
5744                 } else if (iter->base.symbol == NULL) {
5745                         /* search in anonymous structs and unions */
5746                         type_t *type = skip_typeref(iter->declaration.type);
5747                         if (is_type_compound(type)) {
5748                                 if (find_compound_entry(type->compound.compound, symbol)
5749                                                 != NULL)
5750                                         return iter;
5751                         }
5752                         continue;
5753                 }
5754         }
5755
5756         return NULL;
5757 }
5758
5759 static void check_deprecated(const source_position_t *source_position,
5760                              const entity_t *entity)
5761 {
5762         if (!warning.deprecated_declarations)
5763                 return;
5764         if (!is_declaration(entity))
5765                 return;
5766         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5767                 return;
5768
5769         char const *const prefix = get_entity_kind_name(entity->kind);
5770         const char *deprecated_string
5771                         = get_deprecated_string(entity->declaration.attributes);
5772         if (deprecated_string != NULL) {
5773                 warningf(source_position, "%s '%Y' is deprecated (declared %P): \"%s\"",
5774                                  prefix, entity->base.symbol, &entity->base.source_position,
5775                                  deprecated_string);
5776         } else {
5777                 warningf(source_position, "%s '%Y' is deprecated (declared %P)", prefix,
5778                                  entity->base.symbol, &entity->base.source_position);
5779         }
5780 }
5781
5782
5783 static expression_t *create_select(const source_position_t *pos,
5784                                    expression_t *addr,
5785                                    type_qualifiers_t qualifiers,
5786                                                                    entity_t *entry)
5787 {
5788         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5789
5790         check_deprecated(pos, entry);
5791
5792         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5793         select->select.compound       = addr;
5794         select->select.compound_entry = entry;
5795
5796         type_t *entry_type = entry->declaration.type;
5797         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5798
5799         /* we always do the auto-type conversions; the & and sizeof parser contains
5800          * code to revert this! */
5801         select->base.type = automatic_type_conversion(res_type);
5802         if (res_type->kind == TYPE_BITFIELD) {
5803                 select->base.type = res_type->bitfield.base_type;
5804         }
5805
5806         return select;
5807 }
5808
5809 /**
5810  * Find entry with symbol in compound. Search anonymous structs and unions and
5811  * creates implicit select expressions for them.
5812  * Returns the adress for the innermost compound.
5813  */
5814 static expression_t *find_create_select(const source_position_t *pos,
5815                                         expression_t *addr,
5816                                         type_qualifiers_t qualifiers,
5817                                         compound_t *compound, symbol_t *symbol)
5818 {
5819         entity_t *iter = compound->members.entities;
5820         for (; iter != NULL; iter = iter->base.next) {
5821                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5822                         continue;
5823
5824                 symbol_t *iter_symbol = iter->base.symbol;
5825                 if (iter_symbol == NULL) {
5826                         type_t *type = iter->declaration.type;
5827                         if (type->kind != TYPE_COMPOUND_STRUCT
5828                                         && type->kind != TYPE_COMPOUND_UNION)
5829                                 continue;
5830
5831                         compound_t *sub_compound = type->compound.compound;
5832
5833                         if (find_compound_entry(sub_compound, symbol) == NULL)
5834                                 continue;
5835
5836                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5837                         sub_addr->base.source_position = *pos;
5838                         sub_addr->select.implicit      = true;
5839                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5840                                                   symbol);
5841                 }
5842
5843                 if (iter_symbol == symbol) {
5844                         return create_select(pos, addr, qualifiers, iter);
5845                 }
5846         }
5847
5848         return NULL;
5849 }
5850
5851 static void parse_compound_declarators(compound_t *compound,
5852                 const declaration_specifiers_t *specifiers)
5853 {
5854         do {
5855                 entity_t *entity;
5856
5857                 if (token.type == ':') {
5858                         source_position_t source_position = *HERE;
5859                         next_token();
5860
5861                         type_t *base_type = specifiers->type;
5862                         expression_t *size = parse_constant_expression();
5863
5864                         type_t *type = make_bitfield_type(base_type, size,
5865                                         &source_position, NULL);
5866
5867                         attribute_t  *attributes = parse_attributes(NULL);
5868                         attribute_t **anchor     = &attributes;
5869                         while (*anchor != NULL)
5870                                 anchor = &(*anchor)->next;
5871                         *anchor = specifiers->attributes;
5872
5873                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
5874                         entity->base.namespc                       = NAMESPACE_NORMAL;
5875                         entity->base.source_position               = source_position;
5876                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5877                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5878                         entity->declaration.type                   = type;
5879                         entity->declaration.attributes             = attributes;
5880
5881                         if (attributes != NULL) {
5882                                 handle_entity_attributes(attributes, entity);
5883                         }
5884                         append_entity(&compound->members, entity);
5885                 } else {
5886                         entity = parse_declarator(specifiers,
5887                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5888                         if (entity->kind == ENTITY_TYPEDEF) {
5889                                 errorf(&entity->base.source_position,
5890                                                 "typedef not allowed as compound member");
5891                         } else {
5892                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5893
5894                                 /* make sure we don't define a symbol multiple times */
5895                                 symbol_t *symbol = entity->base.symbol;
5896                                 if (symbol != NULL) {
5897                                         entity_t *prev = find_compound_entry(compound, symbol);
5898                                         if (prev != NULL) {
5899                                                 errorf(&entity->base.source_position,
5900                                                                 "multiple declarations of symbol '%Y' (declared %P)",
5901                                                                 symbol, &prev->base.source_position);
5902                                         }
5903                                 }
5904
5905                                 if (token.type == ':') {
5906                                         source_position_t source_position = *HERE;
5907                                         next_token();
5908                                         expression_t *size = parse_constant_expression();
5909
5910                                         type_t *type          = entity->declaration.type;
5911                                         type_t *bitfield_type = make_bitfield_type(type, size,
5912                                                         &source_position, entity->base.symbol);
5913
5914                                         attribute_t *attributes = parse_attributes(NULL);
5915                                         entity->declaration.type = bitfield_type;
5916                                         handle_entity_attributes(attributes, entity);
5917                                 } else {
5918                                         type_t *orig_type = entity->declaration.type;
5919                                         type_t *type      = skip_typeref(orig_type);
5920                                         if (is_type_function(type)) {
5921                                                 errorf(&entity->base.source_position,
5922                                                        "compound member '%Y' must not have function type '%T'",
5923                                                                 entity->base.symbol, orig_type);
5924                                         } else if (is_type_incomplete(type)) {
5925                                                 /* §6.7.2.1:16 flexible array member */
5926                                                 if (!is_type_array(type)       ||
5927                                                                 token.type          != ';' ||
5928                                                                 look_ahead(1)->type != '}') {
5929                                                         errorf(&entity->base.source_position,
5930                                                                "compound member '%Y' has incomplete type '%T'",
5931                                                                         entity->base.symbol, orig_type);
5932                                                 }
5933                                         }
5934                                 }
5935
5936                                 append_entity(&compound->members, entity);
5937                         }
5938                 }
5939         } while (next_if(','));
5940         expect(';', end_error);
5941
5942 end_error:
5943         anonymous_entity = NULL;
5944 }
5945
5946 static void parse_compound_type_entries(compound_t *compound)
5947 {
5948         eat('{');
5949         add_anchor_token('}');
5950
5951         while (token.type != '}') {
5952                 if (token.type == T_EOF) {
5953                         errorf(HERE, "EOF while parsing struct");
5954                         break;
5955                 }
5956                 declaration_specifiers_t specifiers;
5957                 memset(&specifiers, 0, sizeof(specifiers));
5958                 parse_declaration_specifiers(&specifiers);
5959
5960                 parse_compound_declarators(compound, &specifiers);
5961         }
5962         rem_anchor_token('}');
5963         next_token();
5964
5965         /* §6.7.2.1:7 */
5966         compound->complete = true;
5967 }
5968
5969 static type_t *parse_typename(void)
5970 {
5971         declaration_specifiers_t specifiers;
5972         memset(&specifiers, 0, sizeof(specifiers));
5973         parse_declaration_specifiers(&specifiers);
5974         if (specifiers.storage_class != STORAGE_CLASS_NONE
5975                         || specifiers.thread_local) {
5976                 /* TODO: improve error message, user does probably not know what a
5977                  * storage class is...
5978                  */
5979                 errorf(HERE, "typename must not have a storage class");
5980         }
5981
5982         type_t *result = parse_abstract_declarator(specifiers.type);
5983
5984         return result;
5985 }
5986
5987
5988
5989
5990 typedef expression_t* (*parse_expression_function)(void);
5991 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5992
5993 typedef struct expression_parser_function_t expression_parser_function_t;
5994 struct expression_parser_function_t {
5995         parse_expression_function        parser;
5996         precedence_t                     infix_precedence;
5997         parse_expression_infix_function  infix_parser;
5998 };
5999
6000 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6001
6002 /**
6003  * Prints an error message if an expression was expected but not read
6004  */
6005 static expression_t *expected_expression_error(void)
6006 {
6007         /* skip the error message if the error token was read */
6008         if (token.type != T_ERROR) {
6009                 errorf(HERE, "expected expression, got token %K", &token);
6010         }
6011         next_token();
6012
6013         return create_invalid_expression();
6014 }
6015
6016 static type_t *get_string_type(void)
6017 {
6018         return warning.write_strings ? type_const_char_ptr : type_char_ptr;
6019 }
6020
6021 static type_t *get_wide_string_type(void)
6022 {
6023         return warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6024 }
6025
6026 /**
6027  * Parse a string constant.
6028  */
6029 static expression_t *parse_string_literal(void)
6030 {
6031         source_position_t begin   = token.source_position;
6032         string_t          res     = token.literal;
6033         bool              is_wide = (token.type == T_WIDE_STRING_LITERAL);
6034
6035         next_token();
6036         while (token.type == T_STRING_LITERAL
6037                         || token.type == T_WIDE_STRING_LITERAL) {
6038                 warn_string_concat(&token.source_position);
6039                 res = concat_strings(&res, &token.literal);
6040                 next_token();
6041                 is_wide |= token.type == T_WIDE_STRING_LITERAL;
6042         }
6043
6044         expression_t *literal;
6045         if (is_wide) {
6046                 literal = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6047                 literal->base.type = get_wide_string_type();
6048         } else {
6049                 literal = allocate_expression_zero(EXPR_STRING_LITERAL);
6050                 literal->base.type = get_string_type();
6051         }
6052         literal->base.source_position = begin;
6053         literal->literal.value        = res;
6054
6055         return literal;
6056 }
6057
6058 /**
6059  * Parse a boolean constant.
6060  */
6061 static expression_t *parse_boolean_literal(bool value)
6062 {
6063         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
6064         literal->base.source_position = token.source_position;
6065         literal->base.type            = type_bool;
6066         literal->literal.value.begin  = value ? "true" : "false";
6067         literal->literal.value.size   = value ? 4 : 5;
6068
6069         next_token();
6070         return literal;
6071 }
6072
6073 static void warn_traditional_suffix(void)
6074 {
6075         if (!warning.traditional)
6076                 return;
6077         warningf(&token.source_position, "traditional C rejects the '%Y' suffix",
6078                  token.symbol);
6079 }
6080
6081 static void check_integer_suffix(void)
6082 {
6083         symbol_t *suffix = token.symbol;
6084         if (suffix == NULL)
6085                 return;
6086
6087         bool not_traditional = false;
6088         const char *c = suffix->string;
6089         if (*c == 'l' || *c == 'L') {
6090                 ++c;
6091                 if (*c == *(c-1)) {
6092                         not_traditional = true;
6093                         ++c;
6094                         if (*c == 'u' || *c == 'U') {
6095                                 ++c;
6096                         }
6097                 } else if (*c == 'u' || *c == 'U') {
6098                         not_traditional = true;
6099                         ++c;
6100                 }
6101         } else if (*c == 'u' || *c == 'U') {
6102                 not_traditional = true;
6103                 ++c;
6104                 if (*c == 'l' || *c == 'L') {
6105                         ++c;
6106                         if (*c == *(c-1)) {
6107                                 ++c;
6108                         }
6109                 }
6110         }
6111         if (*c != '\0') {
6112                 errorf(&token.source_position,
6113                        "invalid suffix '%s' on integer constant", suffix->string);
6114         } else if (not_traditional) {
6115                 warn_traditional_suffix();
6116         }
6117 }
6118
6119 static type_t *check_floatingpoint_suffix(void)
6120 {
6121         symbol_t *suffix = token.symbol;
6122         type_t   *type   = type_double;
6123         if (suffix == NULL)
6124                 return type;
6125
6126         bool not_traditional = false;
6127         const char *c = suffix->string;
6128         if (*c == 'f' || *c == 'F') {
6129                 ++c;
6130                 type = type_float;
6131         } else if (*c == 'l' || *c == 'L') {
6132                 ++c;
6133                 type = type_long_double;
6134         }
6135         if (*c != '\0') {
6136                 errorf(&token.source_position,
6137                        "invalid suffix '%s' on floatingpoint constant", suffix->string);
6138         } else if (not_traditional) {
6139                 warn_traditional_suffix();
6140         }
6141
6142         return type;
6143 }
6144
6145 /**
6146  * Parse an integer constant.
6147  */
6148 static expression_t *parse_number_literal(void)
6149 {
6150         expression_kind_t  kind;
6151         type_t            *type;
6152
6153         switch (token.type) {
6154         case T_INTEGER:
6155                 kind = EXPR_LITERAL_INTEGER;
6156                 check_integer_suffix();
6157                 type = type_int;
6158                 break;
6159         case T_INTEGER_OCTAL:
6160                 kind = EXPR_LITERAL_INTEGER_OCTAL;
6161                 check_integer_suffix();
6162                 type = type_int;
6163                 break;
6164         case T_INTEGER_HEXADECIMAL:
6165                 kind = EXPR_LITERAL_INTEGER_HEXADECIMAL;
6166                 check_integer_suffix();
6167                 type = type_int;
6168                 break;
6169         case T_FLOATINGPOINT:
6170                 kind = EXPR_LITERAL_FLOATINGPOINT;
6171                 type = check_floatingpoint_suffix();
6172                 break;
6173         case T_FLOATINGPOINT_HEXADECIMAL:
6174                 kind = EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL;
6175                 type = check_floatingpoint_suffix();
6176                 break;
6177         default:
6178                 panic("unexpected token type in parse_number_literal");
6179         }
6180
6181         expression_t *literal = allocate_expression_zero(kind);
6182         literal->base.source_position = token.source_position;
6183         literal->base.type            = type;
6184         literal->literal.value        = token.literal;
6185         literal->literal.suffix       = token.symbol;
6186         next_token();
6187
6188         /* integer type depends on the size of the number and the size
6189          * representable by the types. The backend/codegeneration has to determine
6190          * that
6191          */
6192         determine_literal_type(&literal->literal);
6193         return literal;
6194 }
6195
6196 /**
6197  * Parse a character constant.
6198  */
6199 static expression_t *parse_character_constant(void)
6200 {
6201         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
6202         literal->base.source_position = token.source_position;
6203         literal->base.type            = c_mode & _CXX ? type_char : type_int;
6204         literal->literal.value        = token.literal;
6205
6206         size_t len = literal->literal.value.size;
6207         if (len > 1) {
6208                 if (!GNU_MODE && !(c_mode & _C99)) {
6209                         errorf(HERE, "more than 1 character in character constant");
6210                 } else if (warning.multichar) {
6211                         literal->base.type = type_int;
6212                         warningf(HERE, "multi-character character constant");
6213                 }
6214         }
6215
6216         next_token();
6217         return literal;
6218 }
6219
6220 /**
6221  * Parse a wide character constant.
6222  */
6223 static expression_t *parse_wide_character_constant(void)
6224 {
6225         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
6226         literal->base.source_position = token.source_position;
6227         literal->base.type            = type_int;
6228         literal->literal.value        = token.literal;
6229
6230         size_t len = wstrlen(&literal->literal.value);
6231         if (len > 1) {
6232                 warningf(HERE, "multi-character character constant");
6233         }
6234
6235         next_token();
6236         return literal;
6237 }
6238
6239 static entity_t *create_implicit_function(symbol_t *symbol,
6240                 const source_position_t *source_position)
6241 {
6242         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6243         ntype->function.return_type            = type_int;
6244         ntype->function.unspecified_parameters = true;
6245         ntype->function.linkage                = LINKAGE_C;
6246         type_t *type                           = identify_new_type(ntype);
6247
6248         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6249         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6250         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6251         entity->declaration.type                   = type;
6252         entity->declaration.implicit               = true;
6253         entity->base.namespc                       = NAMESPACE_NORMAL;
6254         entity->base.symbol                        = symbol;
6255         entity->base.source_position               = *source_position;
6256
6257         if (current_scope != NULL) {
6258                 bool strict_prototypes_old = warning.strict_prototypes;
6259                 warning.strict_prototypes  = false;
6260                 record_entity(entity, false);
6261                 warning.strict_prototypes = strict_prototypes_old;
6262         }
6263
6264         return entity;
6265 }
6266
6267 /**
6268  * Performs automatic type cast as described in §6.3.2.1.
6269  *
6270  * @param orig_type  the original type
6271  */
6272 static type_t *automatic_type_conversion(type_t *orig_type)
6273 {
6274         type_t *type = skip_typeref(orig_type);
6275         if (is_type_array(type)) {
6276                 array_type_t *array_type   = &type->array;
6277                 type_t       *element_type = array_type->element_type;
6278                 unsigned      qualifiers   = array_type->base.qualifiers;
6279
6280                 return make_pointer_type(element_type, qualifiers);
6281         }
6282
6283         if (is_type_function(type)) {
6284                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6285         }
6286
6287         return orig_type;
6288 }
6289
6290 /**
6291  * reverts the automatic casts of array to pointer types and function
6292  * to function-pointer types as defined §6.3.2.1
6293  */
6294 type_t *revert_automatic_type_conversion(const expression_t *expression)
6295 {
6296         switch (expression->kind) {
6297         case EXPR_REFERENCE: {
6298                 entity_t *entity = expression->reference.entity;
6299                 if (is_declaration(entity)) {
6300                         return entity->declaration.type;
6301                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
6302                         return entity->enum_value.enum_type;
6303                 } else {
6304                         panic("no declaration or enum in reference");
6305                 }
6306         }
6307
6308         case EXPR_SELECT: {
6309                 entity_t *entity = expression->select.compound_entry;
6310                 assert(is_declaration(entity));
6311                 type_t   *type   = entity->declaration.type;
6312                 return get_qualified_type(type,
6313                                 expression->base.type->base.qualifiers);
6314         }
6315
6316         case EXPR_UNARY_DEREFERENCE: {
6317                 const expression_t *const value = expression->unary.value;
6318                 type_t             *const type  = skip_typeref(value->base.type);
6319                 if (!is_type_pointer(type))
6320                         return type_error_type;
6321                 return type->pointer.points_to;
6322         }
6323
6324         case EXPR_ARRAY_ACCESS: {
6325                 const expression_t *array_ref = expression->array_access.array_ref;
6326                 type_t             *type_left = skip_typeref(array_ref->base.type);
6327                 if (!is_type_pointer(type_left))
6328                         return type_error_type;
6329                 return type_left->pointer.points_to;
6330         }
6331
6332         case EXPR_STRING_LITERAL: {
6333                 size_t size = expression->string_literal.value.size;
6334                 return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6335         }
6336
6337         case EXPR_WIDE_STRING_LITERAL: {
6338                 size_t size = wstrlen(&expression->string_literal.value);
6339                 return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6340         }
6341
6342         case EXPR_COMPOUND_LITERAL:
6343                 return expression->compound_literal.type;
6344
6345         default:
6346                 break;
6347         }
6348         return expression->base.type;
6349 }
6350
6351 /**
6352  * Find an entity matching a symbol in a scope.
6353  * Uses current scope if scope is NULL
6354  */
6355 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6356                                namespace_tag_t namespc)
6357 {
6358         if (scope == NULL) {
6359                 return get_entity(symbol, namespc);
6360         }
6361
6362         /* we should optimize here, if scope grows above a certain size we should
6363            construct a hashmap here... */
6364         entity_t *entity = scope->entities;
6365         for ( ; entity != NULL; entity = entity->base.next) {
6366                 if (entity->base.symbol == symbol && entity->base.namespc == namespc)
6367                         break;
6368         }
6369
6370         return entity;
6371 }
6372
6373 static entity_t *parse_qualified_identifier(void)
6374 {
6375         /* namespace containing the symbol */
6376         symbol_t          *symbol;
6377         source_position_t  pos;
6378         const scope_t     *lookup_scope = NULL;
6379
6380         if (next_if(T_COLONCOLON))
6381                 lookup_scope = &unit->scope;
6382
6383         entity_t *entity;
6384         while (true) {
6385                 if (token.type != T_IDENTIFIER) {
6386                         parse_error_expected("while parsing identifier", T_IDENTIFIER, NULL);
6387                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6388                 }
6389                 symbol = token.symbol;
6390                 pos    = *HERE;
6391                 next_token();
6392
6393                 /* lookup entity */
6394                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6395
6396                 if (!next_if(T_COLONCOLON))
6397                         break;
6398
6399                 switch (entity->kind) {
6400                 case ENTITY_NAMESPACE:
6401                         lookup_scope = &entity->namespacee.members;
6402                         break;
6403                 case ENTITY_STRUCT:
6404                 case ENTITY_UNION:
6405                 case ENTITY_CLASS:
6406                         lookup_scope = &entity->compound.members;
6407                         break;
6408                 default:
6409                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6410                                symbol, get_entity_kind_name(entity->kind));
6411                         goto end_error;
6412                 }
6413         }
6414
6415         if (entity == NULL) {
6416                 if (!strict_mode && token.type == '(') {
6417                         /* an implicitly declared function */
6418                         if (warning.error_implicit_function_declaration) {
6419                                 errorf(&pos, "implicit declaration of function '%Y'", symbol);
6420                         } else if (warning.implicit_function_declaration) {
6421                                 warningf(&pos, "implicit declaration of function '%Y'", symbol);
6422                         }
6423
6424                         entity = create_implicit_function(symbol, &pos);
6425                 } else {
6426                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6427                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6428                 }
6429         }
6430
6431         return entity;
6432
6433 end_error:
6434         /* skip further qualifications */
6435         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6436
6437         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6438 }
6439
6440 static expression_t *parse_reference(void)
6441 {
6442         entity_t *entity = parse_qualified_identifier();
6443
6444         type_t *orig_type;
6445         if (is_declaration(entity)) {
6446                 orig_type = entity->declaration.type;
6447         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6448                 orig_type = entity->enum_value.enum_type;
6449         } else {
6450                 panic("expected declaration or enum value in reference");
6451         }
6452
6453         /* we always do the auto-type conversions; the & and sizeof parser contains
6454          * code to revert this! */
6455         type_t *type = automatic_type_conversion(orig_type);
6456
6457         expression_kind_t kind = EXPR_REFERENCE;
6458         if (entity->kind == ENTITY_ENUM_VALUE)
6459                 kind = EXPR_REFERENCE_ENUM_VALUE;
6460
6461         expression_t *expression     = allocate_expression_zero(kind);
6462         expression->reference.entity = entity;
6463         expression->base.type        = type;
6464
6465         /* this declaration is used */
6466         if (is_declaration(entity)) {
6467                 entity->declaration.used = true;
6468         }
6469
6470         if (entity->base.parent_scope != file_scope
6471                 && (current_function != NULL
6472                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6473                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6474                 if (entity->kind == ENTITY_VARIABLE) {
6475                         /* access of a variable from an outer function */
6476                         entity->variable.address_taken = true;
6477                 } else if (entity->kind == ENTITY_PARAMETER) {
6478                         entity->parameter.address_taken = true;
6479                 }
6480                 current_function->need_closure = true;
6481         }
6482
6483         check_deprecated(HERE, entity);
6484
6485         if (warning.init_self && entity == current_init_decl && !in_type_prop
6486             && entity->kind == ENTITY_VARIABLE) {
6487                 current_init_decl = NULL;
6488                 warningf(HERE, "variable '%#T' is initialized by itself",
6489                          entity->declaration.type, entity->base.symbol);
6490         }
6491
6492         return expression;
6493 }
6494
6495 static bool semantic_cast(expression_t *cast)
6496 {
6497         expression_t            *expression      = cast->unary.value;
6498         type_t                  *orig_dest_type  = cast->base.type;
6499         type_t                  *orig_type_right = expression->base.type;
6500         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6501         type_t            const *src_type        = skip_typeref(orig_type_right);
6502         source_position_t const *pos             = &cast->base.source_position;
6503
6504         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6505         if (dst_type == type_void)
6506                 return true;
6507
6508         /* only integer and pointer can be casted to pointer */
6509         if (is_type_pointer(dst_type)  &&
6510             !is_type_pointer(src_type) &&
6511             !is_type_integer(src_type) &&
6512             is_type_valid(src_type)) {
6513                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6514                 return false;
6515         }
6516
6517         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6518                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6519                 return false;
6520         }
6521
6522         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6523                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6524                 return false;
6525         }
6526
6527         if (warning.cast_qual &&
6528             is_type_pointer(src_type) &&
6529             is_type_pointer(dst_type)) {
6530                 type_t *src = skip_typeref(src_type->pointer.points_to);
6531                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6532                 unsigned missing_qualifiers =
6533                         src->base.qualifiers & ~dst->base.qualifiers;
6534                 if (missing_qualifiers != 0) {
6535                         warningf(pos,
6536                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
6537                                  missing_qualifiers, orig_type_right);
6538                 }
6539         }
6540         return true;
6541 }
6542
6543 static expression_t *parse_compound_literal(type_t *type)
6544 {
6545         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6546
6547         parse_initializer_env_t env;
6548         env.type             = type;
6549         env.entity           = NULL;
6550         env.must_be_constant = false;
6551         initializer_t *initializer = parse_initializer(&env);
6552         type = env.type;
6553
6554         expression->compound_literal.initializer = initializer;
6555         expression->compound_literal.type        = type;
6556         expression->base.type                    = automatic_type_conversion(type);
6557
6558         return expression;
6559 }
6560
6561 /**
6562  * Parse a cast expression.
6563  */
6564 static expression_t *parse_cast(void)
6565 {
6566         add_anchor_token(')');
6567
6568         source_position_t source_position = token.source_position;
6569
6570         type_t *type = parse_typename();
6571
6572         rem_anchor_token(')');
6573         expect(')', end_error);
6574
6575         if (token.type == '{') {
6576                 return parse_compound_literal(type);
6577         }
6578
6579         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6580         cast->base.source_position = source_position;
6581
6582         expression_t *value = parse_subexpression(PREC_CAST);
6583         cast->base.type   = type;
6584         cast->unary.value = value;
6585
6586         if (! semantic_cast(cast)) {
6587                 /* TODO: record the error in the AST. else it is impossible to detect it */
6588         }
6589
6590         return cast;
6591 end_error:
6592         return create_invalid_expression();
6593 }
6594
6595 /**
6596  * Parse a statement expression.
6597  */
6598 static expression_t *parse_statement_expression(void)
6599 {
6600         add_anchor_token(')');
6601
6602         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6603
6604         statement_t *statement          = parse_compound_statement(true);
6605         statement->compound.stmt_expr   = true;
6606         expression->statement.statement = statement;
6607
6608         /* find last statement and use its type */
6609         type_t *type = type_void;
6610         const statement_t *stmt = statement->compound.statements;
6611         if (stmt != NULL) {
6612                 while (stmt->base.next != NULL)
6613                         stmt = stmt->base.next;
6614
6615                 if (stmt->kind == STATEMENT_EXPRESSION) {
6616                         type = stmt->expression.expression->base.type;
6617                 }
6618         } else if (warning.other) {
6619                 warningf(&expression->base.source_position, "empty statement expression ({})");
6620         }
6621         expression->base.type = type;
6622
6623         rem_anchor_token(')');
6624         expect(')', end_error);
6625
6626 end_error:
6627         return expression;
6628 }
6629
6630 /**
6631  * Parse a parenthesized expression.
6632  */
6633 static expression_t *parse_parenthesized_expression(void)
6634 {
6635         eat('(');
6636
6637         switch (token.type) {
6638         case '{':
6639                 /* gcc extension: a statement expression */
6640                 return parse_statement_expression();
6641
6642         TYPE_QUALIFIERS
6643         TYPE_SPECIFIERS
6644                 return parse_cast();
6645         case T_IDENTIFIER:
6646                 if (is_typedef_symbol(token.symbol)) {
6647                         return parse_cast();
6648                 }
6649         }
6650
6651         add_anchor_token(')');
6652         expression_t *result = parse_expression();
6653         result->base.parenthesized = true;
6654         rem_anchor_token(')');
6655         expect(')', end_error);
6656
6657 end_error:
6658         return result;
6659 }
6660
6661 static expression_t *parse_function_keyword(void)
6662 {
6663         /* TODO */
6664
6665         if (current_function == NULL) {
6666                 errorf(HERE, "'__func__' used outside of a function");
6667         }
6668
6669         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6670         expression->base.type     = type_char_ptr;
6671         expression->funcname.kind = FUNCNAME_FUNCTION;
6672
6673         next_token();
6674
6675         return expression;
6676 }
6677
6678 static expression_t *parse_pretty_function_keyword(void)
6679 {
6680         if (current_function == NULL) {
6681                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6682         }
6683
6684         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6685         expression->base.type     = type_char_ptr;
6686         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6687
6688         eat(T___PRETTY_FUNCTION__);
6689
6690         return expression;
6691 }
6692
6693 static expression_t *parse_funcsig_keyword(void)
6694 {
6695         if (current_function == NULL) {
6696                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6697         }
6698
6699         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6700         expression->base.type     = type_char_ptr;
6701         expression->funcname.kind = FUNCNAME_FUNCSIG;
6702
6703         eat(T___FUNCSIG__);
6704
6705         return expression;
6706 }
6707
6708 static expression_t *parse_funcdname_keyword(void)
6709 {
6710         if (current_function == NULL) {
6711                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6712         }
6713
6714         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6715         expression->base.type     = type_char_ptr;
6716         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6717
6718         eat(T___FUNCDNAME__);
6719
6720         return expression;
6721 }
6722
6723 static designator_t *parse_designator(void)
6724 {
6725         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
6726         result->source_position = *HERE;
6727
6728         if (token.type != T_IDENTIFIER) {
6729                 parse_error_expected("while parsing member designator",
6730                                      T_IDENTIFIER, NULL);
6731                 return NULL;
6732         }
6733         result->symbol = token.symbol;
6734         next_token();
6735
6736         designator_t *last_designator = result;
6737         while (true) {
6738                 if (next_if('.')) {
6739                         if (token.type != T_IDENTIFIER) {
6740                                 parse_error_expected("while parsing member designator",
6741                                                      T_IDENTIFIER, NULL);
6742                                 return NULL;
6743                         }
6744                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6745                         designator->source_position = *HERE;
6746                         designator->symbol          = token.symbol;
6747                         next_token();
6748
6749                         last_designator->next = designator;
6750                         last_designator       = designator;
6751                         continue;
6752                 }
6753                 if (next_if('[')) {
6754                         add_anchor_token(']');
6755                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6756                         designator->source_position = *HERE;
6757                         designator->array_index     = parse_expression();
6758                         rem_anchor_token(']');
6759                         expect(']', end_error);
6760                         if (designator->array_index == NULL) {
6761                                 return NULL;
6762                         }
6763
6764                         last_designator->next = designator;
6765                         last_designator       = designator;
6766                         continue;
6767                 }
6768                 break;
6769         }
6770
6771         return result;
6772 end_error:
6773         return NULL;
6774 }
6775
6776 /**
6777  * Parse the __builtin_offsetof() expression.
6778  */
6779 static expression_t *parse_offsetof(void)
6780 {
6781         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6782         expression->base.type    = type_size_t;
6783
6784         eat(T___builtin_offsetof);
6785
6786         expect('(', end_error);
6787         add_anchor_token(',');
6788         type_t *type = parse_typename();
6789         rem_anchor_token(',');
6790         expect(',', end_error);
6791         add_anchor_token(')');
6792         designator_t *designator = parse_designator();
6793         rem_anchor_token(')');
6794         expect(')', end_error);
6795
6796         expression->offsetofe.type       = type;
6797         expression->offsetofe.designator = designator;
6798
6799         type_path_t path;
6800         memset(&path, 0, sizeof(path));
6801         path.top_type = type;
6802         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6803
6804         descend_into_subtype(&path);
6805
6806         if (!walk_designator(&path, designator, true)) {
6807                 return create_invalid_expression();
6808         }
6809
6810         DEL_ARR_F(path.path);
6811
6812         return expression;
6813 end_error:
6814         return create_invalid_expression();
6815 }
6816
6817 /**
6818  * Parses a _builtin_va_start() expression.
6819  */
6820 static expression_t *parse_va_start(void)
6821 {
6822         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6823
6824         eat(T___builtin_va_start);
6825
6826         expect('(', end_error);
6827         add_anchor_token(',');
6828         expression->va_starte.ap = parse_assignment_expression();
6829         rem_anchor_token(',');
6830         expect(',', end_error);
6831         expression_t *const expr = parse_assignment_expression();
6832         if (expr->kind == EXPR_REFERENCE) {
6833                 entity_t *const entity = expr->reference.entity;
6834                 if (!current_function->base.type->function.variadic) {
6835                         errorf(&expr->base.source_position,
6836                                         "'va_start' used in non-variadic function");
6837                 } else if (entity->base.parent_scope != &current_function->parameters ||
6838                                 entity->base.next != NULL ||
6839                                 entity->kind != ENTITY_PARAMETER) {
6840                         errorf(&expr->base.source_position,
6841                                "second argument of 'va_start' must be last parameter of the current function");
6842                 } else {
6843                         expression->va_starte.parameter = &entity->variable;
6844                 }
6845                 expect(')', end_error);
6846                 return expression;
6847         }
6848         expect(')', end_error);
6849 end_error:
6850         return create_invalid_expression();
6851 }
6852
6853 /**
6854  * Parses a __builtin_va_arg() expression.
6855  */
6856 static expression_t *parse_va_arg(void)
6857 {
6858         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6859
6860         eat(T___builtin_va_arg);
6861
6862         expect('(', end_error);
6863         call_argument_t ap;
6864         ap.expression = parse_assignment_expression();
6865         expression->va_arge.ap = ap.expression;
6866         check_call_argument(type_valist, &ap, 1);
6867
6868         expect(',', end_error);
6869         expression->base.type = parse_typename();
6870         expect(')', end_error);
6871
6872         return expression;
6873 end_error:
6874         return create_invalid_expression();
6875 }
6876
6877 /**
6878  * Parses a __builtin_va_copy() expression.
6879  */
6880 static expression_t *parse_va_copy(void)
6881 {
6882         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6883
6884         eat(T___builtin_va_copy);
6885
6886         expect('(', end_error);
6887         expression_t *dst = parse_assignment_expression();
6888         assign_error_t error = semantic_assign(type_valist, dst);
6889         report_assign_error(error, type_valist, dst, "call argument 1",
6890                             &dst->base.source_position);
6891         expression->va_copye.dst = dst;
6892
6893         expect(',', end_error);
6894
6895         call_argument_t src;
6896         src.expression = parse_assignment_expression();
6897         check_call_argument(type_valist, &src, 2);
6898         expression->va_copye.src = src.expression;
6899         expect(')', end_error);
6900
6901         return expression;
6902 end_error:
6903         return create_invalid_expression();
6904 }
6905
6906 /**
6907  * Parses a __builtin_constant_p() expression.
6908  */
6909 static expression_t *parse_builtin_constant(void)
6910 {
6911         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6912
6913         eat(T___builtin_constant_p);
6914
6915         expect('(', end_error);
6916         add_anchor_token(')');
6917         expression->builtin_constant.value = parse_assignment_expression();
6918         rem_anchor_token(')');
6919         expect(')', end_error);
6920         expression->base.type = type_int;
6921
6922         return expression;
6923 end_error:
6924         return create_invalid_expression();
6925 }
6926
6927 /**
6928  * Parses a __builtin_types_compatible_p() expression.
6929  */
6930 static expression_t *parse_builtin_types_compatible(void)
6931 {
6932         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6933
6934         eat(T___builtin_types_compatible_p);
6935
6936         expect('(', end_error);
6937         add_anchor_token(')');
6938         add_anchor_token(',');
6939         expression->builtin_types_compatible.left = parse_typename();
6940         rem_anchor_token(',');
6941         expect(',', end_error);
6942         expression->builtin_types_compatible.right = parse_typename();
6943         rem_anchor_token(')');
6944         expect(')', end_error);
6945         expression->base.type = type_int;
6946
6947         return expression;
6948 end_error:
6949         return create_invalid_expression();
6950 }
6951
6952 /**
6953  * Parses a __builtin_is_*() compare expression.
6954  */
6955 static expression_t *parse_compare_builtin(void)
6956 {
6957         expression_t *expression;
6958
6959         switch (token.type) {
6960         case T___builtin_isgreater:
6961                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6962                 break;
6963         case T___builtin_isgreaterequal:
6964                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6965                 break;
6966         case T___builtin_isless:
6967                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6968                 break;
6969         case T___builtin_islessequal:
6970                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6971                 break;
6972         case T___builtin_islessgreater:
6973                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6974                 break;
6975         case T___builtin_isunordered:
6976                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6977                 break;
6978         default:
6979                 internal_errorf(HERE, "invalid compare builtin found");
6980         }
6981         expression->base.source_position = *HERE;
6982         next_token();
6983
6984         expect('(', end_error);
6985         expression->binary.left = parse_assignment_expression();
6986         expect(',', end_error);
6987         expression->binary.right = parse_assignment_expression();
6988         expect(')', end_error);
6989
6990         type_t *const orig_type_left  = expression->binary.left->base.type;
6991         type_t *const orig_type_right = expression->binary.right->base.type;
6992
6993         type_t *const type_left  = skip_typeref(orig_type_left);
6994         type_t *const type_right = skip_typeref(orig_type_right);
6995         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6996                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6997                         type_error_incompatible("invalid operands in comparison",
6998                                 &expression->base.source_position, orig_type_left, orig_type_right);
6999                 }
7000         } else {
7001                 semantic_comparison(&expression->binary);
7002         }
7003
7004         return expression;
7005 end_error:
7006         return create_invalid_expression();
7007 }
7008
7009 /**
7010  * Parses a MS assume() expression.
7011  */
7012 static expression_t *parse_assume(void)
7013 {
7014         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7015
7016         eat(T__assume);
7017
7018         expect('(', end_error);
7019         add_anchor_token(')');
7020         expression->unary.value = parse_assignment_expression();
7021         rem_anchor_token(')');
7022         expect(')', end_error);
7023
7024         expression->base.type = type_void;
7025         return expression;
7026 end_error:
7027         return create_invalid_expression();
7028 }
7029
7030 /**
7031  * Return the declaration for a given label symbol or create a new one.
7032  *
7033  * @param symbol  the symbol of the label
7034  */
7035 static label_t *get_label(symbol_t *symbol)
7036 {
7037         entity_t *label;
7038         assert(current_function != NULL);
7039
7040         label = get_entity(symbol, NAMESPACE_LABEL);
7041         /* if we found a local label, we already created the declaration */
7042         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7043                 if (label->base.parent_scope != current_scope) {
7044                         assert(label->base.parent_scope->depth < current_scope->depth);
7045                         current_function->goto_to_outer = true;
7046                 }
7047                 return &label->label;
7048         }
7049
7050         label = get_entity(symbol, NAMESPACE_LABEL);
7051         /* if we found a label in the same function, then we already created the
7052          * declaration */
7053         if (label != NULL
7054                         && label->base.parent_scope == &current_function->parameters) {
7055                 return &label->label;
7056         }
7057
7058         /* otherwise we need to create a new one */
7059         label               = allocate_entity_zero(ENTITY_LABEL);
7060         label->base.namespc = NAMESPACE_LABEL;
7061         label->base.symbol  = symbol;
7062
7063         label_push(label);
7064
7065         return &label->label;
7066 }
7067
7068 /**
7069  * Parses a GNU && label address expression.
7070  */
7071 static expression_t *parse_label_address(void)
7072 {
7073         source_position_t source_position = token.source_position;
7074         eat(T_ANDAND);
7075         if (token.type != T_IDENTIFIER) {
7076                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7077                 goto end_error;
7078         }
7079         symbol_t *symbol = token.symbol;
7080         next_token();
7081
7082         label_t *label       = get_label(symbol);
7083         label->used          = true;
7084         label->address_taken = true;
7085
7086         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7087         expression->base.source_position = source_position;
7088
7089         /* label address is threaten as a void pointer */
7090         expression->base.type           = type_void_ptr;
7091         expression->label_address.label = label;
7092         return expression;
7093 end_error:
7094         return create_invalid_expression();
7095 }
7096
7097 /**
7098  * Parse a microsoft __noop expression.
7099  */
7100 static expression_t *parse_noop_expression(void)
7101 {
7102         /* the result is a (int)0 */
7103         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
7104         literal->base.type            = type_int;
7105         literal->base.source_position = token.source_position;
7106         literal->literal.value.begin  = "__noop";
7107         literal->literal.value.size   = 6;
7108
7109         eat(T___noop);
7110
7111         if (token.type == '(') {
7112                 /* parse arguments */
7113                 eat('(');
7114                 add_anchor_token(')');
7115                 add_anchor_token(',');
7116
7117                 if (token.type != ')') do {
7118                         (void)parse_assignment_expression();
7119                 } while (next_if(','));
7120         }
7121         rem_anchor_token(',');
7122         rem_anchor_token(')');
7123         expect(')', end_error);
7124
7125 end_error:
7126         return literal;
7127 }
7128
7129 /**
7130  * Parses a primary expression.
7131  */
7132 static expression_t *parse_primary_expression(void)
7133 {
7134         switch (token.type) {
7135         case T_false:                        return parse_boolean_literal(false);
7136         case T_true:                         return parse_boolean_literal(true);
7137         case T_INTEGER:
7138         case T_INTEGER_OCTAL:
7139         case T_INTEGER_HEXADECIMAL:
7140         case T_FLOATINGPOINT:
7141         case T_FLOATINGPOINT_HEXADECIMAL:    return parse_number_literal();
7142         case T_CHARACTER_CONSTANT:           return parse_character_constant();
7143         case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
7144         case T_STRING_LITERAL:
7145         case T_WIDE_STRING_LITERAL:          return parse_string_literal();
7146         case T___FUNCTION__:
7147         case T___func__:                     return parse_function_keyword();
7148         case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
7149         case T___FUNCSIG__:                  return parse_funcsig_keyword();
7150         case T___FUNCDNAME__:                return parse_funcdname_keyword();
7151         case T___builtin_offsetof:           return parse_offsetof();
7152         case T___builtin_va_start:           return parse_va_start();
7153         case T___builtin_va_arg:             return parse_va_arg();
7154         case T___builtin_va_copy:            return parse_va_copy();
7155         case T___builtin_isgreater:
7156         case T___builtin_isgreaterequal:
7157         case T___builtin_isless:
7158         case T___builtin_islessequal:
7159         case T___builtin_islessgreater:
7160         case T___builtin_isunordered:        return parse_compare_builtin();
7161         case T___builtin_constant_p:         return parse_builtin_constant();
7162         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
7163         case T__assume:                      return parse_assume();
7164         case T_ANDAND:
7165                 if (GNU_MODE)
7166                         return parse_label_address();
7167                 break;
7168
7169         case '(':                            return parse_parenthesized_expression();
7170         case T___noop:                       return parse_noop_expression();
7171
7172         /* Gracefully handle type names while parsing expressions. */
7173         case T_COLONCOLON:
7174                 return parse_reference();
7175         case T_IDENTIFIER:
7176                 if (!is_typedef_symbol(token.symbol)) {
7177                         return parse_reference();
7178                 }
7179                 /* FALLTHROUGH */
7180         TYPENAME_START {
7181                 source_position_t  const pos  = *HERE;
7182                 type_t const      *const type = parse_typename();
7183                 errorf(&pos, "encountered type '%T' while parsing expression", type);
7184                 return create_invalid_expression();
7185         }
7186         }
7187
7188         errorf(HERE, "unexpected token %K, expected an expression", &token);
7189         eat_until_anchor();
7190         return create_invalid_expression();
7191 }
7192
7193 static expression_t *parse_array_expression(expression_t *left)
7194 {
7195         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7196         array_access_expression_t *const arr  = &expr->array_access;
7197
7198         eat('[');
7199         add_anchor_token(']');
7200
7201         expression_t *const inside = parse_expression();
7202
7203         type_t *const orig_type_left   = left->base.type;
7204         type_t *const orig_type_inside = inside->base.type;
7205
7206         type_t *const type_left   = skip_typeref(orig_type_left);
7207         type_t *const type_inside = skip_typeref(orig_type_inside);
7208
7209         expression_t *ref;
7210         expression_t *idx;
7211         type_t       *idx_type;
7212         type_t       *res_type;
7213         if (is_type_pointer(type_left)) {
7214                 ref      = left;
7215                 idx      = inside;
7216                 idx_type = type_inside;
7217                 res_type = type_left->pointer.points_to;
7218                 goto check_idx;
7219         } else if (is_type_pointer(type_inside)) {
7220                 arr->flipped = true;
7221                 ref      = inside;
7222                 idx      = left;
7223                 idx_type = type_left;
7224                 res_type = type_inside->pointer.points_to;
7225 check_idx:
7226                 res_type = automatic_type_conversion(res_type);
7227                 if (!is_type_integer(idx_type)) {
7228                         errorf(&idx->base.source_position, "array subscript must have integer type");
7229                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR) && warning.char_subscripts) {
7230                         warningf(&idx->base.source_position, "array subscript has char type");
7231                 }
7232         } else {
7233                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7234                         errorf(HERE,
7235                                 "array access on object with non-pointer types '%T', '%T'",
7236                                 orig_type_left, orig_type_inside);
7237                 }
7238                 res_type = type_error_type;
7239                 ref      = left;
7240                 idx      = inside;
7241         }
7242
7243         arr->array_ref = ref;
7244         arr->index     = idx;
7245         arr->base.type = res_type;
7246
7247         rem_anchor_token(']');
7248         expect(']', end_error);
7249 end_error:
7250         return expr;
7251 }
7252
7253 static expression_t *parse_typeprop(expression_kind_t const kind)
7254 {
7255         expression_t  *tp_expression = allocate_expression_zero(kind);
7256         tp_expression->base.type     = type_size_t;
7257
7258         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7259
7260         /* we only refer to a type property, mark this case */
7261         bool old     = in_type_prop;
7262         in_type_prop = true;
7263
7264         type_t       *orig_type;
7265         expression_t *expression;
7266         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7267                 next_token();
7268                 add_anchor_token(')');
7269                 orig_type = parse_typename();
7270                 rem_anchor_token(')');
7271                 expect(')', end_error);
7272
7273                 if (token.type == '{') {
7274                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7275                          * starting with a compound literal */
7276                         expression = parse_compound_literal(orig_type);
7277                         goto typeprop_expression;
7278                 }
7279         } else {
7280                 expression = parse_subexpression(PREC_UNARY);
7281
7282 typeprop_expression:
7283                 tp_expression->typeprop.tp_expression = expression;
7284
7285                 orig_type = revert_automatic_type_conversion(expression);
7286                 expression->base.type = orig_type;
7287         }
7288
7289         tp_expression->typeprop.type   = orig_type;
7290         type_t const* const type       = skip_typeref(orig_type);
7291         char   const*       wrong_type = NULL;
7292         if (is_type_incomplete(type)) {
7293                 if (!is_type_atomic(type, ATOMIC_TYPE_VOID) || !GNU_MODE)
7294                         wrong_type = "incomplete";
7295         } else if (type->kind == TYPE_FUNCTION) {
7296                 if (GNU_MODE) {
7297                         /* function types are allowed (and return 1) */
7298                         if (warning.other) {
7299                                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7300                                 warningf(&tp_expression->base.source_position,
7301                                          "%s expression with function argument returns invalid result", what);
7302                         }
7303                 } else {
7304                         wrong_type = "function";
7305                 }
7306         } else {
7307                 if (is_type_incomplete(type))
7308                         wrong_type = "incomplete";
7309         }
7310         if (type->kind == TYPE_BITFIELD)
7311                 wrong_type = "bitfield";
7312
7313         if (wrong_type != NULL) {
7314                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7315                 errorf(&tp_expression->base.source_position,
7316                                 "operand of %s expression must not be of %s type '%T'",
7317                                 what, wrong_type, orig_type);
7318         }
7319
7320 end_error:
7321         in_type_prop = old;
7322         return tp_expression;
7323 }
7324
7325 static expression_t *parse_sizeof(void)
7326 {
7327         return parse_typeprop(EXPR_SIZEOF);
7328 }
7329
7330 static expression_t *parse_alignof(void)
7331 {
7332         return parse_typeprop(EXPR_ALIGNOF);
7333 }
7334
7335 static expression_t *parse_select_expression(expression_t *addr)
7336 {
7337         assert(token.type == '.' || token.type == T_MINUSGREATER);
7338         bool select_left_arrow = (token.type == T_MINUSGREATER);
7339         source_position_t const pos = *HERE;
7340         next_token();
7341
7342         if (token.type != T_IDENTIFIER) {
7343                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7344                 return create_invalid_expression();
7345         }
7346         symbol_t *symbol = token.symbol;
7347         next_token();
7348
7349         type_t *const orig_type = addr->base.type;
7350         type_t *const type      = skip_typeref(orig_type);
7351
7352         type_t *type_left;
7353         bool    saw_error = false;
7354         if (is_type_pointer(type)) {
7355                 if (!select_left_arrow) {
7356                         errorf(&pos,
7357                                "request for member '%Y' in something not a struct or union, but '%T'",
7358                                symbol, orig_type);
7359                         saw_error = true;
7360                 }
7361                 type_left = skip_typeref(type->pointer.points_to);
7362         } else {
7363                 if (select_left_arrow && is_type_valid(type)) {
7364                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7365                         saw_error = true;
7366                 }
7367                 type_left = type;
7368         }
7369
7370         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
7371             type_left->kind != TYPE_COMPOUND_UNION) {
7372
7373                 if (is_type_valid(type_left) && !saw_error) {
7374                         errorf(&pos,
7375                                "request for member '%Y' in something not a struct or union, but '%T'",
7376                                symbol, type_left);
7377                 }
7378                 return create_invalid_expression();
7379         }
7380
7381         compound_t *compound = type_left->compound.compound;
7382         if (!compound->complete) {
7383                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
7384                        symbol, type_left);
7385                 return create_invalid_expression();
7386         }
7387
7388         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
7389         expression_t      *result     =
7390                 find_create_select(&pos, addr, qualifiers, compound, symbol);
7391
7392         if (result == NULL) {
7393                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
7394                 return create_invalid_expression();
7395         }
7396
7397         return result;
7398 }
7399
7400 static void check_call_argument(type_t          *expected_type,
7401                                 call_argument_t *argument, unsigned pos)
7402 {
7403         type_t         *expected_type_skip = skip_typeref(expected_type);
7404         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7405         expression_t   *arg_expr           = argument->expression;
7406         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7407
7408         /* handle transparent union gnu extension */
7409         if (is_type_union(expected_type_skip)
7410                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7411                 compound_t *union_decl  = expected_type_skip->compound.compound;
7412                 type_t     *best_type   = NULL;
7413                 entity_t   *entry       = union_decl->members.entities;
7414                 for ( ; entry != NULL; entry = entry->base.next) {
7415                         assert(is_declaration(entry));
7416                         type_t *decl_type = entry->declaration.type;
7417                         error = semantic_assign(decl_type, arg_expr);
7418                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7419                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7420                                 continue;
7421
7422                         if (error == ASSIGN_SUCCESS) {
7423                                 best_type = decl_type;
7424                         } else if (best_type == NULL) {
7425                                 best_type = decl_type;
7426                         }
7427                 }
7428
7429                 if (best_type != NULL) {
7430                         expected_type = best_type;
7431                 }
7432         }
7433
7434         error                = semantic_assign(expected_type, arg_expr);
7435         argument->expression = create_implicit_cast(arg_expr, expected_type);
7436
7437         if (error != ASSIGN_SUCCESS) {
7438                 /* report exact scope in error messages (like "in argument 3") */
7439                 char buf[64];
7440                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7441                 report_assign_error(error, expected_type, arg_expr, buf,
7442                                     &arg_expr->base.source_position);
7443         } else if (warning.traditional || warning.conversion) {
7444                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7445                 if (!types_compatible(expected_type_skip, promoted_type) &&
7446                     !types_compatible(expected_type_skip, type_void_ptr) &&
7447                     !types_compatible(type_void_ptr,      promoted_type)) {
7448                         /* Deliberately show the skipped types in this warning */
7449                         warningf(&arg_expr->base.source_position,
7450                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
7451                                 pos, expected_type_skip, promoted_type);
7452                 }
7453         }
7454 }
7455
7456 /**
7457  * Handle the semantic restrictions of builtin calls
7458  */
7459 static void handle_builtin_argument_restrictions(call_expression_t *call) {
7460         switch (call->function->reference.entity->function.btk) {
7461                 case bk_gnu_builtin_return_address:
7462                 case bk_gnu_builtin_frame_address: {
7463                         /* argument must be constant */
7464                         call_argument_t *argument = call->arguments;
7465
7466                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7467                                 errorf(&call->base.source_position,
7468                                        "argument of '%Y' must be a constant expression",
7469                                        call->function->reference.entity->base.symbol);
7470                         }
7471                         break;
7472                 }
7473                 case bk_gnu_builtin_object_size:
7474                         if (call->arguments == NULL)
7475                                 break;
7476
7477                         call_argument_t *arg = call->arguments->next;
7478                         if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7479                                 errorf(&call->base.source_position,
7480                                            "second argument of '%Y' must be a constant expression",
7481                                            call->function->reference.entity->base.symbol);
7482                         }
7483                         break;
7484                 case bk_gnu_builtin_prefetch:
7485                         /* second and third argument must be constant if existent */
7486                         if (call->arguments == NULL)
7487                                 break;
7488                         call_argument_t *rw = call->arguments->next;
7489                         call_argument_t *locality = NULL;
7490
7491                         if (rw != NULL) {
7492                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7493                                         errorf(&call->base.source_position,
7494                                                "second argument of '%Y' must be a constant expression",
7495                                                call->function->reference.entity->base.symbol);
7496                                 }
7497                                 locality = rw->next;
7498                         }
7499                         if (locality != NULL) {
7500                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7501                                         errorf(&call->base.source_position,
7502                                                "third argument of '%Y' must be a constant expression",
7503                                                call->function->reference.entity->base.symbol);
7504                                 }
7505                                 locality = rw->next;
7506                         }
7507                         break;
7508                 default:
7509                         break;
7510         }
7511 }
7512
7513 /**
7514  * Parse a call expression, ie. expression '( ... )'.
7515  *
7516  * @param expression  the function address
7517  */
7518 static expression_t *parse_call_expression(expression_t *expression)
7519 {
7520         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7521         call_expression_t *call   = &result->call;
7522         call->function            = expression;
7523
7524         type_t *const orig_type = expression->base.type;
7525         type_t *const type      = skip_typeref(orig_type);
7526
7527         function_type_t *function_type = NULL;
7528         if (is_type_pointer(type)) {
7529                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7530
7531                 if (is_type_function(to_type)) {
7532                         function_type   = &to_type->function;
7533                         call->base.type = function_type->return_type;
7534                 }
7535         }
7536
7537         if (function_type == NULL && is_type_valid(type)) {
7538                 errorf(HERE,
7539                        "called object '%E' (type '%T') is not a pointer to a function",
7540                        expression, orig_type);
7541         }
7542
7543         /* parse arguments */
7544         eat('(');
7545         add_anchor_token(')');
7546         add_anchor_token(',');
7547
7548         if (token.type != ')') {
7549                 call_argument_t **anchor = &call->arguments;
7550                 do {
7551                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7552                         argument->expression = parse_assignment_expression();
7553
7554                         *anchor = argument;
7555                         anchor  = &argument->next;
7556                 } while (next_if(','));
7557         }
7558         rem_anchor_token(',');
7559         rem_anchor_token(')');
7560         expect(')', end_error);
7561
7562         if (function_type == NULL)
7563                 return result;
7564
7565         /* check type and count of call arguments */
7566         function_parameter_t *parameter = function_type->parameters;
7567         call_argument_t      *argument  = call->arguments;
7568         if (!function_type->unspecified_parameters) {
7569                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7570                                 parameter = parameter->next, argument = argument->next) {
7571                         check_call_argument(parameter->type, argument, ++pos);
7572                 }
7573
7574                 if (parameter != NULL) {
7575                         errorf(HERE, "too few arguments to function '%E'", expression);
7576                 } else if (argument != NULL && !function_type->variadic) {
7577                         errorf(HERE, "too many arguments to function '%E'", expression);
7578                 }
7579         }
7580
7581         /* do default promotion for other arguments */
7582         for (; argument != NULL; argument = argument->next) {
7583                 type_t *type = argument->expression->base.type;
7584                 if (!is_type_object(skip_typeref(type))) {
7585                         errorf(&argument->expression->base.source_position,
7586                                "call argument '%E' must not be void", argument->expression);
7587                 }
7588
7589                 type = get_default_promoted_type(type);
7590
7591                 argument->expression
7592                         = create_implicit_cast(argument->expression, type);
7593         }
7594
7595         check_format(&result->call);
7596
7597         if (warning.aggregate_return &&
7598             is_type_compound(skip_typeref(function_type->return_type))) {
7599                 warningf(&result->base.source_position,
7600                          "function call has aggregate value");
7601         }
7602
7603         if (call->function->kind == EXPR_REFERENCE) {
7604                 reference_expression_t *reference = &call->function->reference;
7605                 if (reference->entity->kind == ENTITY_FUNCTION &&
7606                     reference->entity->function.btk != bk_none)
7607                         handle_builtin_argument_restrictions(call);
7608         }
7609
7610 end_error:
7611         return result;
7612 }
7613
7614 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7615
7616 static bool same_compound_type(const type_t *type1, const type_t *type2)
7617 {
7618         return
7619                 is_type_compound(type1) &&
7620                 type1->kind == type2->kind &&
7621                 type1->compound.compound == type2->compound.compound;
7622 }
7623
7624 static expression_t const *get_reference_address(expression_t const *expr)
7625 {
7626         bool regular_take_address = true;
7627         for (;;) {
7628                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7629                         expr = expr->unary.value;
7630                 } else {
7631                         regular_take_address = false;
7632                 }
7633
7634                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7635                         break;
7636
7637                 expr = expr->unary.value;
7638         }
7639
7640         if (expr->kind != EXPR_REFERENCE)
7641                 return NULL;
7642
7643         /* special case for functions which are automatically converted to a
7644          * pointer to function without an extra TAKE_ADDRESS operation */
7645         if (!regular_take_address &&
7646                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7647                 return NULL;
7648         }
7649
7650         return expr;
7651 }
7652
7653 static void warn_reference_address_as_bool(expression_t const* expr)
7654 {
7655         if (!warning.address)
7656                 return;
7657
7658         expr = get_reference_address(expr);
7659         if (expr != NULL) {
7660                 warningf(&expr->base.source_position,
7661                          "the address of '%Y' will always evaluate as 'true'",
7662                          expr->reference.entity->base.symbol);
7663         }
7664 }
7665
7666 static void warn_assignment_in_condition(const expression_t *const expr)
7667 {
7668         if (!warning.parentheses)
7669                 return;
7670         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7671                 return;
7672         if (expr->base.parenthesized)
7673                 return;
7674         warningf(&expr->base.source_position,
7675                         "suggest parentheses around assignment used as truth value");
7676 }
7677
7678 static void semantic_condition(expression_t const *const expr,
7679                                char const *const context)
7680 {
7681         type_t *const type = skip_typeref(expr->base.type);
7682         if (is_type_scalar(type)) {
7683                 warn_reference_address_as_bool(expr);
7684                 warn_assignment_in_condition(expr);
7685         } else if (is_type_valid(type)) {
7686                 errorf(&expr->base.source_position,
7687                                 "%s must have scalar type", context);
7688         }
7689 }
7690
7691 /**
7692  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7693  *
7694  * @param expression  the conditional expression
7695  */
7696 static expression_t *parse_conditional_expression(expression_t *expression)
7697 {
7698         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7699
7700         conditional_expression_t *conditional = &result->conditional;
7701         conditional->condition                = expression;
7702
7703         eat('?');
7704         add_anchor_token(':');
7705
7706         /* §6.5.15:2  The first operand shall have scalar type. */
7707         semantic_condition(expression, "condition of conditional operator");
7708
7709         expression_t *true_expression = expression;
7710         bool          gnu_cond = false;
7711         if (GNU_MODE && token.type == ':') {
7712                 gnu_cond = true;
7713         } else {
7714                 true_expression = parse_expression();
7715         }
7716         rem_anchor_token(':');
7717         expect(':', end_error);
7718 end_error:;
7719         expression_t *false_expression =
7720                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7721
7722         type_t *const orig_true_type  = true_expression->base.type;
7723         type_t *const orig_false_type = false_expression->base.type;
7724         type_t *const true_type       = skip_typeref(orig_true_type);
7725         type_t *const false_type      = skip_typeref(orig_false_type);
7726
7727         /* 6.5.15.3 */
7728         type_t *result_type;
7729         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7730                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
7731                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7732                 if (true_expression->kind == EXPR_UNARY_THROW) {
7733                         result_type = false_type;
7734                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7735                         result_type = true_type;
7736                 } else {
7737                         if (warning.other && (
7738                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7739                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
7740                                         )) {
7741                                 warningf(&conditional->base.source_position,
7742                                                 "ISO C forbids conditional expression with only one void side");
7743                         }
7744                         result_type = type_void;
7745                 }
7746         } else if (is_type_arithmetic(true_type)
7747                    && is_type_arithmetic(false_type)) {
7748                 result_type = semantic_arithmetic(true_type, false_type);
7749         } else if (same_compound_type(true_type, false_type)) {
7750                 /* just take 1 of the 2 types */
7751                 result_type = true_type;
7752         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7753                 type_t *pointer_type;
7754                 type_t *other_type;
7755                 expression_t *other_expression;
7756                 if (is_type_pointer(true_type) &&
7757                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7758                         pointer_type     = true_type;
7759                         other_type       = false_type;
7760                         other_expression = false_expression;
7761                 } else {
7762                         pointer_type     = false_type;
7763                         other_type       = true_type;
7764                         other_expression = true_expression;
7765                 }
7766
7767                 if (is_null_pointer_constant(other_expression)) {
7768                         result_type = pointer_type;
7769                 } else if (is_type_pointer(other_type)) {
7770                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7771                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7772
7773                         type_t *to;
7774                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
7775                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
7776                                 to = type_void;
7777                         } else if (types_compatible(get_unqualified_type(to1),
7778                                                     get_unqualified_type(to2))) {
7779                                 to = to1;
7780                         } else {
7781                                 if (warning.other) {
7782                                         warningf(&conditional->base.source_position,
7783                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
7784                                                         true_type, false_type);
7785                                 }
7786                                 to = type_void;
7787                         }
7788
7789                         type_t *const type =
7790                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7791                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7792                 } else if (is_type_integer(other_type)) {
7793                         if (warning.other) {
7794                                 warningf(&conditional->base.source_position,
7795                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7796                         }
7797                         result_type = pointer_type;
7798                 } else {
7799                         if (is_type_valid(other_type)) {
7800                                 type_error_incompatible("while parsing conditional",
7801                                                 &expression->base.source_position, true_type, false_type);
7802                         }
7803                         result_type = type_error_type;
7804                 }
7805         } else {
7806                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7807                         type_error_incompatible("while parsing conditional",
7808                                                 &conditional->base.source_position, true_type,
7809                                                 false_type);
7810                 }
7811                 result_type = type_error_type;
7812         }
7813
7814         conditional->true_expression
7815                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7816         conditional->false_expression
7817                 = create_implicit_cast(false_expression, result_type);
7818         conditional->base.type = result_type;
7819         return result;
7820 }
7821
7822 /**
7823  * Parse an extension expression.
7824  */
7825 static expression_t *parse_extension(void)
7826 {
7827         eat(T___extension__);
7828
7829         bool old_gcc_extension   = in_gcc_extension;
7830         in_gcc_extension         = true;
7831         expression_t *expression = parse_subexpression(PREC_UNARY);
7832         in_gcc_extension         = old_gcc_extension;
7833         return expression;
7834 }
7835
7836 /**
7837  * Parse a __builtin_classify_type() expression.
7838  */
7839 static expression_t *parse_builtin_classify_type(void)
7840 {
7841         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7842         result->base.type    = type_int;
7843
7844         eat(T___builtin_classify_type);
7845
7846         expect('(', end_error);
7847         add_anchor_token(')');
7848         expression_t *expression = parse_expression();
7849         rem_anchor_token(')');
7850         expect(')', end_error);
7851         result->classify_type.type_expression = expression;
7852
7853         return result;
7854 end_error:
7855         return create_invalid_expression();
7856 }
7857
7858 /**
7859  * Parse a delete expression
7860  * ISO/IEC 14882:1998(E) §5.3.5
7861  */
7862 static expression_t *parse_delete(void)
7863 {
7864         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7865         result->base.type          = type_void;
7866
7867         eat(T_delete);
7868
7869         if (next_if('[')) {
7870                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7871                 expect(']', end_error);
7872 end_error:;
7873         }
7874
7875         expression_t *const value = parse_subexpression(PREC_CAST);
7876         result->unary.value = value;
7877
7878         type_t *const type = skip_typeref(value->base.type);
7879         if (!is_type_pointer(type)) {
7880                 if (is_type_valid(type)) {
7881                         errorf(&value->base.source_position,
7882                                         "operand of delete must have pointer type");
7883                 }
7884         } else if (warning.other &&
7885                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
7886                 warningf(&value->base.source_position,
7887                                 "deleting 'void*' is undefined");
7888         }
7889
7890         return result;
7891 }
7892
7893 /**
7894  * Parse a throw expression
7895  * ISO/IEC 14882:1998(E) §15:1
7896  */
7897 static expression_t *parse_throw(void)
7898 {
7899         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7900         result->base.type          = type_void;
7901
7902         eat(T_throw);
7903
7904         expression_t *value = NULL;
7905         switch (token.type) {
7906                 EXPRESSION_START {
7907                         value = parse_assignment_expression();
7908                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7909                         type_t *const orig_type = value->base.type;
7910                         type_t *const type      = skip_typeref(orig_type);
7911                         if (is_type_incomplete(type)) {
7912                                 errorf(&value->base.source_position,
7913                                                 "cannot throw object of incomplete type '%T'", orig_type);
7914                         } else if (is_type_pointer(type)) {
7915                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7916                                 if (is_type_incomplete(points_to) &&
7917                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7918                                         errorf(&value->base.source_position,
7919                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7920                                 }
7921                         }
7922                 }
7923
7924                 default:
7925                         break;
7926         }
7927         result->unary.value = value;
7928
7929         return result;
7930 }
7931
7932 static bool check_pointer_arithmetic(const source_position_t *source_position,
7933                                      type_t *pointer_type,
7934                                      type_t *orig_pointer_type)
7935 {
7936         type_t *points_to = pointer_type->pointer.points_to;
7937         points_to = skip_typeref(points_to);
7938
7939         if (is_type_incomplete(points_to)) {
7940                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7941                         errorf(source_position,
7942                                "arithmetic with pointer to incomplete type '%T' not allowed",
7943                                orig_pointer_type);
7944                         return false;
7945                 } else if (warning.pointer_arith) {
7946                         warningf(source_position,
7947                                  "pointer of type '%T' used in arithmetic",
7948                                  orig_pointer_type);
7949                 }
7950         } else if (is_type_function(points_to)) {
7951                 if (!GNU_MODE) {
7952                         errorf(source_position,
7953                                "arithmetic with pointer to function type '%T' not allowed",
7954                                orig_pointer_type);
7955                         return false;
7956                 } else if (warning.pointer_arith) {
7957                         warningf(source_position,
7958                                  "pointer to a function '%T' used in arithmetic",
7959                                  orig_pointer_type);
7960                 }
7961         }
7962         return true;
7963 }
7964
7965 static bool is_lvalue(const expression_t *expression)
7966 {
7967         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7968         switch (expression->kind) {
7969         case EXPR_ARRAY_ACCESS:
7970         case EXPR_COMPOUND_LITERAL:
7971         case EXPR_REFERENCE:
7972         case EXPR_SELECT:
7973         case EXPR_UNARY_DEREFERENCE:
7974                 return true;
7975
7976         default: {
7977                 type_t *type = skip_typeref(expression->base.type);
7978                 return
7979                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7980                         is_type_reference(type) ||
7981                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7982                          * error before, which maybe prevented properly recognizing it as
7983                          * lvalue. */
7984                         !is_type_valid(type);
7985         }
7986         }
7987 }
7988
7989 static void semantic_incdec(unary_expression_t *expression)
7990 {
7991         type_t *const orig_type = expression->value->base.type;
7992         type_t *const type      = skip_typeref(orig_type);
7993         if (is_type_pointer(type)) {
7994                 if (!check_pointer_arithmetic(&expression->base.source_position,
7995                                               type, orig_type)) {
7996                         return;
7997                 }
7998         } else if (!is_type_real(type) && is_type_valid(type)) {
7999                 /* TODO: improve error message */
8000                 errorf(&expression->base.source_position,
8001                        "operation needs an arithmetic or pointer type");
8002                 return;
8003         }
8004         if (!is_lvalue(expression->value)) {
8005                 /* TODO: improve error message */
8006                 errorf(&expression->base.source_position, "lvalue required as operand");
8007         }
8008         expression->base.type = orig_type;
8009 }
8010
8011 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8012 {
8013         type_t *const orig_type = expression->value->base.type;
8014         type_t *const type      = skip_typeref(orig_type);
8015         if (!is_type_arithmetic(type)) {
8016                 if (is_type_valid(type)) {
8017                         /* TODO: improve error message */
8018                         errorf(&expression->base.source_position,
8019                                 "operation needs an arithmetic type");
8020                 }
8021                 return;
8022         }
8023
8024         expression->base.type = orig_type;
8025 }
8026
8027 static void semantic_unexpr_plus(unary_expression_t *expression)
8028 {
8029         semantic_unexpr_arithmetic(expression);
8030         if (warning.traditional)
8031                 warningf(&expression->base.source_position,
8032                         "traditional C rejects the unary plus operator");
8033 }
8034
8035 static void semantic_not(unary_expression_t *expression)
8036 {
8037         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
8038         semantic_condition(expression->value, "operand of !");
8039         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8040 }
8041
8042 static void semantic_unexpr_integer(unary_expression_t *expression)
8043 {
8044         type_t *const orig_type = expression->value->base.type;
8045         type_t *const type      = skip_typeref(orig_type);
8046         if (!is_type_integer(type)) {
8047                 if (is_type_valid(type)) {
8048                         errorf(&expression->base.source_position,
8049                                "operand of ~ must be of integer type");
8050                 }
8051                 return;
8052         }
8053
8054         expression->base.type = orig_type;
8055 }
8056
8057 static void semantic_dereference(unary_expression_t *expression)
8058 {
8059         type_t *const orig_type = expression->value->base.type;
8060         type_t *const type      = skip_typeref(orig_type);
8061         if (!is_type_pointer(type)) {
8062                 if (is_type_valid(type)) {
8063                         errorf(&expression->base.source_position,
8064                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8065                 }
8066                 return;
8067         }
8068
8069         type_t *result_type   = type->pointer.points_to;
8070         result_type           = automatic_type_conversion(result_type);
8071         expression->base.type = result_type;
8072 }
8073
8074 /**
8075  * Record that an address is taken (expression represents an lvalue).
8076  *
8077  * @param expression       the expression
8078  * @param may_be_register  if true, the expression might be an register
8079  */
8080 static void set_address_taken(expression_t *expression, bool may_be_register)
8081 {
8082         if (expression->kind != EXPR_REFERENCE)
8083                 return;
8084
8085         entity_t *const entity = expression->reference.entity;
8086
8087         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
8088                 return;
8089
8090         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8091                         && !may_be_register) {
8092                 errorf(&expression->base.source_position,
8093                        "address of register %s '%Y' requested",
8094                        get_entity_kind_name(entity->kind), entity->base.symbol);
8095         }
8096
8097         if (entity->kind == ENTITY_VARIABLE) {
8098                 entity->variable.address_taken = true;
8099         } else {
8100                 assert(entity->kind == ENTITY_PARAMETER);
8101                 entity->parameter.address_taken = true;
8102         }
8103 }
8104
8105 /**
8106  * Check the semantic of the address taken expression.
8107  */
8108 static void semantic_take_addr(unary_expression_t *expression)
8109 {
8110         expression_t *value = expression->value;
8111         value->base.type    = revert_automatic_type_conversion(value);
8112
8113         type_t *orig_type = value->base.type;
8114         type_t *type      = skip_typeref(orig_type);
8115         if (!is_type_valid(type))
8116                 return;
8117
8118         /* §6.5.3.2 */
8119         if (!is_lvalue(value)) {
8120                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8121         }
8122         if (type->kind == TYPE_BITFIELD) {
8123                 errorf(&expression->base.source_position,
8124                        "'&' not allowed on object with bitfield type '%T'",
8125                        type);
8126         }
8127
8128         set_address_taken(value, false);
8129
8130         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8131 }
8132
8133 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8134 static expression_t *parse_##unexpression_type(void)                         \
8135 {                                                                            \
8136         expression_t *unary_expression                                           \
8137                 = allocate_expression_zero(unexpression_type);                       \
8138         eat(token_type);                                                         \
8139         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
8140                                                                                  \
8141         sfunc(&unary_expression->unary);                                         \
8142                                                                                  \
8143         return unary_expression;                                                 \
8144 }
8145
8146 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8147                                semantic_unexpr_arithmetic)
8148 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8149                                semantic_unexpr_plus)
8150 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8151                                semantic_not)
8152 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8153                                semantic_dereference)
8154 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8155                                semantic_take_addr)
8156 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8157                                semantic_unexpr_integer)
8158 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8159                                semantic_incdec)
8160 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8161                                semantic_incdec)
8162
8163 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8164                                                sfunc)                         \
8165 static expression_t *parse_##unexpression_type(expression_t *left)            \
8166 {                                                                             \
8167         expression_t *unary_expression                                            \
8168                 = allocate_expression_zero(unexpression_type);                        \
8169         eat(token_type);                                                          \
8170         unary_expression->unary.value = left;                                     \
8171                                                                                   \
8172         sfunc(&unary_expression->unary);                                          \
8173                                                                               \
8174         return unary_expression;                                                  \
8175 }
8176
8177 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8178                                        EXPR_UNARY_POSTFIX_INCREMENT,
8179                                        semantic_incdec)
8180 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8181                                        EXPR_UNARY_POSTFIX_DECREMENT,
8182                                        semantic_incdec)
8183
8184 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8185 {
8186         /* TODO: handle complex + imaginary types */
8187
8188         type_left  = get_unqualified_type(type_left);
8189         type_right = get_unqualified_type(type_right);
8190
8191         /* §6.3.1.8 Usual arithmetic conversions */
8192         if (type_left == type_long_double || type_right == type_long_double) {
8193                 return type_long_double;
8194         } else if (type_left == type_double || type_right == type_double) {
8195                 return type_double;
8196         } else if (type_left == type_float || type_right == type_float) {
8197                 return type_float;
8198         }
8199
8200         type_left  = promote_integer(type_left);
8201         type_right = promote_integer(type_right);
8202
8203         if (type_left == type_right)
8204                 return type_left;
8205
8206         bool const signed_left  = is_type_signed(type_left);
8207         bool const signed_right = is_type_signed(type_right);
8208         int const  rank_left    = get_rank(type_left);
8209         int const  rank_right   = get_rank(type_right);
8210
8211         if (signed_left == signed_right)
8212                 return rank_left >= rank_right ? type_left : type_right;
8213
8214         int     s_rank;
8215         int     u_rank;
8216         type_t *s_type;
8217         type_t *u_type;
8218         if (signed_left) {
8219                 s_rank = rank_left;
8220                 s_type = type_left;
8221                 u_rank = rank_right;
8222                 u_type = type_right;
8223         } else {
8224                 s_rank = rank_right;
8225                 s_type = type_right;
8226                 u_rank = rank_left;
8227                 u_type = type_left;
8228         }
8229
8230         if (u_rank >= s_rank)
8231                 return u_type;
8232
8233         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8234          * easier here... */
8235         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8236                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8237                 return s_type;
8238
8239         switch (s_rank) {
8240                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8241                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8242                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8243
8244                 default: panic("invalid atomic type");
8245         }
8246 }
8247
8248 /**
8249  * Check the semantic restrictions for a binary expression.
8250  */
8251 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8252 {
8253         expression_t *const left            = expression->left;
8254         expression_t *const right           = expression->right;
8255         type_t       *const orig_type_left  = left->base.type;
8256         type_t       *const orig_type_right = right->base.type;
8257         type_t       *const type_left       = skip_typeref(orig_type_left);
8258         type_t       *const type_right      = skip_typeref(orig_type_right);
8259
8260         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8261                 /* TODO: improve error message */
8262                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8263                         errorf(&expression->base.source_position,
8264                                "operation needs arithmetic types");
8265                 }
8266                 return;
8267         }
8268
8269         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8270         expression->left      = create_implicit_cast(left, arithmetic_type);
8271         expression->right     = create_implicit_cast(right, arithmetic_type);
8272         expression->base.type = arithmetic_type;
8273 }
8274
8275 static void semantic_binexpr_integer(binary_expression_t *const expression)
8276 {
8277         expression_t *const left            = expression->left;
8278         expression_t *const right           = expression->right;
8279         type_t       *const orig_type_left  = left->base.type;
8280         type_t       *const orig_type_right = right->base.type;
8281         type_t       *const type_left       = skip_typeref(orig_type_left);
8282         type_t       *const type_right      = skip_typeref(orig_type_right);
8283
8284         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8285                 /* TODO: improve error message */
8286                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8287                         errorf(&expression->base.source_position,
8288                                "operation needs integer types");
8289                 }
8290                 return;
8291         }
8292
8293         type_t *const result_type = semantic_arithmetic(type_left, type_right);
8294         expression->left      = create_implicit_cast(left, result_type);
8295         expression->right     = create_implicit_cast(right, result_type);
8296         expression->base.type = result_type;
8297 }
8298
8299 static void warn_div_by_zero(binary_expression_t const *const expression)
8300 {
8301         if (!warning.div_by_zero ||
8302             !is_type_integer(expression->base.type))
8303                 return;
8304
8305         expression_t const *const right = expression->right;
8306         /* The type of the right operand can be different for /= */
8307         if (is_type_integer(right->base.type)                    &&
8308             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
8309             !fold_constant_to_bool(right)) {
8310                 warningf(&expression->base.source_position, "division by zero");
8311         }
8312 }
8313
8314 /**
8315  * Check the semantic restrictions for a div/mod expression.
8316  */
8317 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8318 {
8319         semantic_binexpr_arithmetic(expression);
8320         warn_div_by_zero(expression);
8321 }
8322
8323 static void warn_addsub_in_shift(const expression_t *const expr)
8324 {
8325         if (expr->base.parenthesized)
8326                 return;
8327
8328         char op;
8329         switch (expr->kind) {
8330                 case EXPR_BINARY_ADD: op = '+'; break;
8331                 case EXPR_BINARY_SUB: op = '-'; break;
8332                 default:              return;
8333         }
8334
8335         warningf(&expr->base.source_position,
8336                         "suggest parentheses around '%c' inside shift", op);
8337 }
8338
8339 static bool semantic_shift(binary_expression_t *expression)
8340 {
8341         expression_t *const left            = expression->left;
8342         expression_t *const right           = expression->right;
8343         type_t       *const orig_type_left  = left->base.type;
8344         type_t       *const orig_type_right = right->base.type;
8345         type_t       *      type_left       = skip_typeref(orig_type_left);
8346         type_t       *      type_right      = skip_typeref(orig_type_right);
8347
8348         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8349                 /* TODO: improve error message */
8350                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8351                         errorf(&expression->base.source_position,
8352                                "operands of shift operation must have integer types");
8353                 }
8354                 return false;
8355         }
8356
8357         type_left = promote_integer(type_left);
8358
8359         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
8360                 long count = fold_constant_to_int(right);
8361                 if (count < 0) {
8362                         warningf(&right->base.source_position,
8363                                         "shift count must be non-negative");
8364                 } else if ((unsigned long)count >=
8365                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
8366                         warningf(&right->base.source_position,
8367                                         "shift count must be less than type width");
8368                 }
8369         }
8370
8371         type_right        = promote_integer(type_right);
8372         expression->right = create_implicit_cast(right, type_right);
8373
8374         return true;
8375 }
8376
8377 static void semantic_shift_op(binary_expression_t *expression)
8378 {
8379         expression_t *const left  = expression->left;
8380         expression_t *const right = expression->right;
8381
8382         if (!semantic_shift(expression))
8383                 return;
8384
8385         if (warning.parentheses) {
8386                 warn_addsub_in_shift(left);
8387                 warn_addsub_in_shift(right);
8388         }
8389
8390         type_t *const orig_type_left = left->base.type;
8391         type_t *      type_left      = skip_typeref(orig_type_left);
8392
8393         type_left             = promote_integer(type_left);
8394         expression->left      = create_implicit_cast(left, type_left);
8395         expression->base.type = type_left;
8396 }
8397
8398 static void semantic_add(binary_expression_t *expression)
8399 {
8400         expression_t *const left            = expression->left;
8401         expression_t *const right           = expression->right;
8402         type_t       *const orig_type_left  = left->base.type;
8403         type_t       *const orig_type_right = right->base.type;
8404         type_t       *const type_left       = skip_typeref(orig_type_left);
8405         type_t       *const type_right      = skip_typeref(orig_type_right);
8406
8407         /* §6.5.6 */
8408         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8409                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8410                 expression->left  = create_implicit_cast(left, arithmetic_type);
8411                 expression->right = create_implicit_cast(right, arithmetic_type);
8412                 expression->base.type = arithmetic_type;
8413         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8414                 check_pointer_arithmetic(&expression->base.source_position,
8415                                          type_left, orig_type_left);
8416                 expression->base.type = type_left;
8417         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8418                 check_pointer_arithmetic(&expression->base.source_position,
8419                                          type_right, orig_type_right);
8420                 expression->base.type = type_right;
8421         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8422                 errorf(&expression->base.source_position,
8423                        "invalid operands to binary + ('%T', '%T')",
8424                        orig_type_left, orig_type_right);
8425         }
8426 }
8427
8428 static void semantic_sub(binary_expression_t *expression)
8429 {
8430         expression_t            *const left            = expression->left;
8431         expression_t            *const right           = expression->right;
8432         type_t                  *const orig_type_left  = left->base.type;
8433         type_t                  *const orig_type_right = right->base.type;
8434         type_t                  *const type_left       = skip_typeref(orig_type_left);
8435         type_t                  *const type_right      = skip_typeref(orig_type_right);
8436         source_position_t const *const pos             = &expression->base.source_position;
8437
8438         /* §5.6.5 */
8439         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8440                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8441                 expression->left        = create_implicit_cast(left, arithmetic_type);
8442                 expression->right       = create_implicit_cast(right, arithmetic_type);
8443                 expression->base.type =  arithmetic_type;
8444         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8445                 check_pointer_arithmetic(&expression->base.source_position,
8446                                          type_left, orig_type_left);
8447                 expression->base.type = type_left;
8448         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8449                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8450                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8451                 if (!types_compatible(unqual_left, unqual_right)) {
8452                         errorf(pos,
8453                                "subtracting pointers to incompatible types '%T' and '%T'",
8454                                orig_type_left, orig_type_right);
8455                 } else if (!is_type_object(unqual_left)) {
8456                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8457                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8458                                        orig_type_left);
8459                         } else if (warning.other) {
8460                                 warningf(pos, "subtracting pointers to void");
8461                         }
8462                 }
8463                 expression->base.type = type_ptrdiff_t;
8464         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8465                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8466                        orig_type_left, orig_type_right);
8467         }
8468 }
8469
8470 static void warn_string_literal_address(expression_t const* expr)
8471 {
8472         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8473                 expr = expr->unary.value;
8474                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8475                         return;
8476                 expr = expr->unary.value;
8477         }
8478
8479         if (expr->kind == EXPR_STRING_LITERAL
8480                         || expr->kind == EXPR_WIDE_STRING_LITERAL) {
8481                 warningf(&expr->base.source_position,
8482                         "comparison with string literal results in unspecified behaviour");
8483         }
8484 }
8485
8486 static void warn_comparison_in_comparison(const expression_t *const expr)
8487 {
8488         if (expr->base.parenthesized)
8489                 return;
8490         switch (expr->base.kind) {
8491                 case EXPR_BINARY_LESS:
8492                 case EXPR_BINARY_GREATER:
8493                 case EXPR_BINARY_LESSEQUAL:
8494                 case EXPR_BINARY_GREATEREQUAL:
8495                 case EXPR_BINARY_NOTEQUAL:
8496                 case EXPR_BINARY_EQUAL:
8497                         warningf(&expr->base.source_position,
8498                                         "comparisons like 'x <= y < z' do not have their mathematical meaning");
8499                         break;
8500                 default:
8501                         break;
8502         }
8503 }
8504
8505 static bool maybe_negative(expression_t const *const expr)
8506 {
8507         switch (is_constant_expression(expr)) {
8508                 case EXPR_CLASS_ERROR:    return false;
8509                 case EXPR_CLASS_CONSTANT: return fold_constant_to_int(expr) < 0;
8510                 default:                  return true;
8511         }
8512 }
8513
8514 /**
8515  * Check the semantics of comparison expressions.
8516  *
8517  * @param expression   The expression to check.
8518  */
8519 static void semantic_comparison(binary_expression_t *expression)
8520 {
8521         expression_t *left  = expression->left;
8522         expression_t *right = expression->right;
8523
8524         if (warning.address) {
8525                 warn_string_literal_address(left);
8526                 warn_string_literal_address(right);
8527
8528                 expression_t const* const func_left = get_reference_address(left);
8529                 if (func_left != NULL && is_null_pointer_constant(right)) {
8530                         warningf(&expression->base.source_position,
8531                                  "the address of '%Y' will never be NULL",
8532                                  func_left->reference.entity->base.symbol);
8533                 }
8534
8535                 expression_t const* const func_right = get_reference_address(right);
8536                 if (func_right != NULL && is_null_pointer_constant(right)) {
8537                         warningf(&expression->base.source_position,
8538                                  "the address of '%Y' will never be NULL",
8539                                  func_right->reference.entity->base.symbol);
8540                 }
8541         }
8542
8543         if (warning.parentheses) {
8544                 warn_comparison_in_comparison(left);
8545                 warn_comparison_in_comparison(right);
8546         }
8547
8548         type_t *orig_type_left  = left->base.type;
8549         type_t *orig_type_right = right->base.type;
8550         type_t *type_left       = skip_typeref(orig_type_left);
8551         type_t *type_right      = skip_typeref(orig_type_right);
8552
8553         /* TODO non-arithmetic types */
8554         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8555                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8556
8557                 /* test for signed vs unsigned compares */
8558                 if (warning.sign_compare && is_type_integer(arithmetic_type)) {
8559                         bool const signed_left  = is_type_signed(type_left);
8560                         bool const signed_right = is_type_signed(type_right);
8561                         if (signed_left != signed_right) {
8562                                 /* FIXME long long needs better const folding magic */
8563                                 /* TODO check whether constant value can be represented by other type */
8564                                 if ((signed_left  && maybe_negative(left)) ||
8565                                                 (signed_right && maybe_negative(right))) {
8566                                         warningf(&expression->base.source_position,
8567                                                         "comparison between signed and unsigned");
8568                                 }
8569                         }
8570                 }
8571
8572                 expression->left        = create_implicit_cast(left, arithmetic_type);
8573                 expression->right       = create_implicit_cast(right, arithmetic_type);
8574                 expression->base.type   = arithmetic_type;
8575                 if (warning.float_equal &&
8576                     (expression->base.kind == EXPR_BINARY_EQUAL ||
8577                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8578                     is_type_float(arithmetic_type)) {
8579                         warningf(&expression->base.source_position,
8580                                  "comparing floating point with == or != is unsafe");
8581                 }
8582         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8583                 /* TODO check compatibility */
8584         } else if (is_type_pointer(type_left)) {
8585                 expression->right = create_implicit_cast(right, type_left);
8586         } else if (is_type_pointer(type_right)) {
8587                 expression->left = create_implicit_cast(left, type_right);
8588         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8589                 type_error_incompatible("invalid operands in comparison",
8590                                         &expression->base.source_position,
8591                                         type_left, type_right);
8592         }
8593         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8594 }
8595
8596 /**
8597  * Checks if a compound type has constant fields.
8598  */
8599 static bool has_const_fields(const compound_type_t *type)
8600 {
8601         compound_t *compound = type->compound;
8602         entity_t   *entry    = compound->members.entities;
8603
8604         for (; entry != NULL; entry = entry->base.next) {
8605                 if (!is_declaration(entry))
8606                         continue;
8607
8608                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8609                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8610                         return true;
8611         }
8612
8613         return false;
8614 }
8615
8616 static bool is_valid_assignment_lhs(expression_t const* const left)
8617 {
8618         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8619         type_t *const type_left      = skip_typeref(orig_type_left);
8620
8621         if (!is_lvalue(left)) {
8622                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
8623                        left);
8624                 return false;
8625         }
8626
8627         if (left->kind == EXPR_REFERENCE
8628                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8629                 errorf(HERE, "cannot assign to function '%E'", left);
8630                 return false;
8631         }
8632
8633         if (is_type_array(type_left)) {
8634                 errorf(HERE, "cannot assign to array '%E'", left);
8635                 return false;
8636         }
8637         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8638                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
8639                        orig_type_left);
8640                 return false;
8641         }
8642         if (is_type_incomplete(type_left)) {
8643                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
8644                        left, orig_type_left);
8645                 return false;
8646         }
8647         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8648                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
8649                        left, orig_type_left);
8650                 return false;
8651         }
8652
8653         return true;
8654 }
8655
8656 static void semantic_arithmetic_assign(binary_expression_t *expression)
8657 {
8658         expression_t *left            = expression->left;
8659         expression_t *right           = expression->right;
8660         type_t       *orig_type_left  = left->base.type;
8661         type_t       *orig_type_right = right->base.type;
8662
8663         if (!is_valid_assignment_lhs(left))
8664                 return;
8665
8666         type_t *type_left  = skip_typeref(orig_type_left);
8667         type_t *type_right = skip_typeref(orig_type_right);
8668
8669         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8670                 /* TODO: improve error message */
8671                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8672                         errorf(&expression->base.source_position,
8673                                "operation needs arithmetic types");
8674                 }
8675                 return;
8676         }
8677
8678         /* combined instructions are tricky. We can't create an implicit cast on
8679          * the left side, because we need the uncasted form for the store.
8680          * The ast2firm pass has to know that left_type must be right_type
8681          * for the arithmetic operation and create a cast by itself */
8682         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8683         expression->right       = create_implicit_cast(right, arithmetic_type);
8684         expression->base.type   = type_left;
8685 }
8686
8687 static void semantic_divmod_assign(binary_expression_t *expression)
8688 {
8689         semantic_arithmetic_assign(expression);
8690         warn_div_by_zero(expression);
8691 }
8692
8693 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8694 {
8695         expression_t *const left            = expression->left;
8696         expression_t *const right           = expression->right;
8697         type_t       *const orig_type_left  = left->base.type;
8698         type_t       *const orig_type_right = right->base.type;
8699         type_t       *const type_left       = skip_typeref(orig_type_left);
8700         type_t       *const type_right      = skip_typeref(orig_type_right);
8701
8702         if (!is_valid_assignment_lhs(left))
8703                 return;
8704
8705         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8706                 /* combined instructions are tricky. We can't create an implicit cast on
8707                  * the left side, because we need the uncasted form for the store.
8708                  * The ast2firm pass has to know that left_type must be right_type
8709                  * for the arithmetic operation and create a cast by itself */
8710                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8711                 expression->right     = create_implicit_cast(right, arithmetic_type);
8712                 expression->base.type = type_left;
8713         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8714                 check_pointer_arithmetic(&expression->base.source_position,
8715                                          type_left, orig_type_left);
8716                 expression->base.type = type_left;
8717         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8718                 errorf(&expression->base.source_position,
8719                        "incompatible types '%T' and '%T' in assignment",
8720                        orig_type_left, orig_type_right);
8721         }
8722 }
8723
8724 static void semantic_integer_assign(binary_expression_t *expression)
8725 {
8726         expression_t *left            = expression->left;
8727         expression_t *right           = expression->right;
8728         type_t       *orig_type_left  = left->base.type;
8729         type_t       *orig_type_right = right->base.type;
8730
8731         if (!is_valid_assignment_lhs(left))
8732                 return;
8733
8734         type_t *type_left  = skip_typeref(orig_type_left);
8735         type_t *type_right = skip_typeref(orig_type_right);
8736
8737         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8738                 /* TODO: improve error message */
8739                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8740                         errorf(&expression->base.source_position,
8741                                "operation needs integer types");
8742                 }
8743                 return;
8744         }
8745
8746         /* combined instructions are tricky. We can't create an implicit cast on
8747          * the left side, because we need the uncasted form for the store.
8748          * The ast2firm pass has to know that left_type must be right_type
8749          * for the arithmetic operation and create a cast by itself */
8750         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8751         expression->right       = create_implicit_cast(right, arithmetic_type);
8752         expression->base.type   = type_left;
8753 }
8754
8755 static void semantic_shift_assign(binary_expression_t *expression)
8756 {
8757         expression_t *left           = expression->left;
8758
8759         if (!is_valid_assignment_lhs(left))
8760                 return;
8761
8762         if (!semantic_shift(expression))
8763                 return;
8764
8765         expression->base.type = skip_typeref(left->base.type);
8766 }
8767
8768 static void warn_logical_and_within_or(const expression_t *const expr)
8769 {
8770         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8771                 return;
8772         if (expr->base.parenthesized)
8773                 return;
8774         warningf(&expr->base.source_position,
8775                         "suggest parentheses around && within ||");
8776 }
8777
8778 /**
8779  * Check the semantic restrictions of a logical expression.
8780  */
8781 static void semantic_logical_op(binary_expression_t *expression)
8782 {
8783         /* §6.5.13:2  Each of the operands shall have scalar type.
8784          * §6.5.14:2  Each of the operands shall have scalar type. */
8785         semantic_condition(expression->left,   "left operand of logical operator");
8786         semantic_condition(expression->right, "right operand of logical operator");
8787         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
8788                         warning.parentheses) {
8789                 warn_logical_and_within_or(expression->left);
8790                 warn_logical_and_within_or(expression->right);
8791         }
8792         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8793 }
8794
8795 /**
8796  * Check the semantic restrictions of a binary assign expression.
8797  */
8798 static void semantic_binexpr_assign(binary_expression_t *expression)
8799 {
8800         expression_t *left           = expression->left;
8801         type_t       *orig_type_left = left->base.type;
8802
8803         if (!is_valid_assignment_lhs(left))
8804                 return;
8805
8806         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8807         report_assign_error(error, orig_type_left, expression->right,
8808                         "assignment", &left->base.source_position);
8809         expression->right = create_implicit_cast(expression->right, orig_type_left);
8810         expression->base.type = orig_type_left;
8811 }
8812
8813 /**
8814  * Determine if the outermost operation (or parts thereof) of the given
8815  * expression has no effect in order to generate a warning about this fact.
8816  * Therefore in some cases this only examines some of the operands of the
8817  * expression (see comments in the function and examples below).
8818  * Examples:
8819  *   f() + 23;    // warning, because + has no effect
8820  *   x || f();    // no warning, because x controls execution of f()
8821  *   x ? y : f(); // warning, because y has no effect
8822  *   (void)x;     // no warning to be able to suppress the warning
8823  * This function can NOT be used for an "expression has definitely no effect"-
8824  * analysis. */
8825 static bool expression_has_effect(const expression_t *const expr)
8826 {
8827         switch (expr->kind) {
8828                 case EXPR_UNKNOWN:                    break;
8829                 case EXPR_INVALID:                    return true; /* do NOT warn */
8830                 case EXPR_REFERENCE:                  return false;
8831                 case EXPR_REFERENCE_ENUM_VALUE:       return false;
8832                 case EXPR_LABEL_ADDRESS:              return false;
8833
8834                 /* suppress the warning for microsoft __noop operations */
8835                 case EXPR_LITERAL_MS_NOOP:            return true;
8836                 case EXPR_LITERAL_BOOLEAN:
8837                 case EXPR_LITERAL_CHARACTER:
8838                 case EXPR_LITERAL_WIDE_CHARACTER:
8839                 case EXPR_LITERAL_INTEGER:
8840                 case EXPR_LITERAL_INTEGER_OCTAL:
8841                 case EXPR_LITERAL_INTEGER_HEXADECIMAL:
8842                 case EXPR_LITERAL_FLOATINGPOINT:
8843                 case EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL: return false;
8844                 case EXPR_STRING_LITERAL:             return false;
8845                 case EXPR_WIDE_STRING_LITERAL:        return false;
8846
8847                 case EXPR_CALL: {
8848                         const call_expression_t *const call = &expr->call;
8849                         if (call->function->kind != EXPR_REFERENCE)
8850                                 return true;
8851
8852                         switch (call->function->reference.entity->function.btk) {
8853                                 /* FIXME: which builtins have no effect? */
8854                                 default:                      return true;
8855                         }
8856                 }
8857
8858                 /* Generate the warning if either the left or right hand side of a
8859                  * conditional expression has no effect */
8860                 case EXPR_CONDITIONAL: {
8861                         conditional_expression_t const *const cond = &expr->conditional;
8862                         expression_t             const *const t    = cond->true_expression;
8863                         return
8864                                 (t == NULL || expression_has_effect(t)) &&
8865                                 expression_has_effect(cond->false_expression);
8866                 }
8867
8868                 case EXPR_SELECT:                     return false;
8869                 case EXPR_ARRAY_ACCESS:               return false;
8870                 case EXPR_SIZEOF:                     return false;
8871                 case EXPR_CLASSIFY_TYPE:              return false;
8872                 case EXPR_ALIGNOF:                    return false;
8873
8874                 case EXPR_FUNCNAME:                   return false;
8875                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8876                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8877                 case EXPR_OFFSETOF:                   return false;
8878                 case EXPR_VA_START:                   return true;
8879                 case EXPR_VA_ARG:                     return true;
8880                 case EXPR_VA_COPY:                    return true;
8881                 case EXPR_STATEMENT:                  return true; // TODO
8882                 case EXPR_COMPOUND_LITERAL:           return false;
8883
8884                 case EXPR_UNARY_NEGATE:               return false;
8885                 case EXPR_UNARY_PLUS:                 return false;
8886                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8887                 case EXPR_UNARY_NOT:                  return false;
8888                 case EXPR_UNARY_DEREFERENCE:          return false;
8889                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8890                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8891                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8892                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8893                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8894
8895                 /* Treat void casts as if they have an effect in order to being able to
8896                  * suppress the warning */
8897                 case EXPR_UNARY_CAST: {
8898                         type_t *const type = skip_typeref(expr->base.type);
8899                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
8900                 }
8901
8902                 case EXPR_UNARY_CAST_IMPLICIT:        return true;
8903                 case EXPR_UNARY_ASSUME:               return true;
8904                 case EXPR_UNARY_DELETE:               return true;
8905                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8906                 case EXPR_UNARY_THROW:                return true;
8907
8908                 case EXPR_BINARY_ADD:                 return false;
8909                 case EXPR_BINARY_SUB:                 return false;
8910                 case EXPR_BINARY_MUL:                 return false;
8911                 case EXPR_BINARY_DIV:                 return false;
8912                 case EXPR_BINARY_MOD:                 return false;
8913                 case EXPR_BINARY_EQUAL:               return false;
8914                 case EXPR_BINARY_NOTEQUAL:            return false;
8915                 case EXPR_BINARY_LESS:                return false;
8916                 case EXPR_BINARY_LESSEQUAL:           return false;
8917                 case EXPR_BINARY_GREATER:             return false;
8918                 case EXPR_BINARY_GREATEREQUAL:        return false;
8919                 case EXPR_BINARY_BITWISE_AND:         return false;
8920                 case EXPR_BINARY_BITWISE_OR:          return false;
8921                 case EXPR_BINARY_BITWISE_XOR:         return false;
8922                 case EXPR_BINARY_SHIFTLEFT:           return false;
8923                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8924                 case EXPR_BINARY_ASSIGN:              return true;
8925                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8926                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8927                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8928                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8929                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8930                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8931                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8932                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8933                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8934                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8935
8936                 /* Only examine the right hand side of && and ||, because the left hand
8937                  * side already has the effect of controlling the execution of the right
8938                  * hand side */
8939                 case EXPR_BINARY_LOGICAL_AND:
8940                 case EXPR_BINARY_LOGICAL_OR:
8941                 /* Only examine the right hand side of a comma expression, because the left
8942                  * hand side has a separate warning */
8943                 case EXPR_BINARY_COMMA:
8944                         return expression_has_effect(expr->binary.right);
8945
8946                 case EXPR_BINARY_ISGREATER:           return false;
8947                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8948                 case EXPR_BINARY_ISLESS:              return false;
8949                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8950                 case EXPR_BINARY_ISLESSGREATER:       return false;
8951                 case EXPR_BINARY_ISUNORDERED:         return false;
8952         }
8953
8954         internal_errorf(HERE, "unexpected expression");
8955 }
8956
8957 static void semantic_comma(binary_expression_t *expression)
8958 {
8959         if (warning.unused_value) {
8960                 const expression_t *const left = expression->left;
8961                 if (!expression_has_effect(left)) {
8962                         warningf(&left->base.source_position,
8963                                  "left-hand operand of comma expression has no effect");
8964                 }
8965         }
8966         expression->base.type = expression->right->base.type;
8967 }
8968
8969 /**
8970  * @param prec_r precedence of the right operand
8971  */
8972 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
8973 static expression_t *parse_##binexpression_type(expression_t *left)          \
8974 {                                                                            \
8975         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8976         binexpr->binary.left  = left;                                            \
8977         eat(token_type);                                                         \
8978                                                                              \
8979         expression_t *right = parse_subexpression(prec_r);                       \
8980                                                                              \
8981         binexpr->binary.right = right;                                           \
8982         sfunc(&binexpr->binary);                                                 \
8983                                                                              \
8984         return binexpr;                                                          \
8985 }
8986
8987 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8988 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8989 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8990 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8991 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8992 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8993 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8994 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8995 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8996 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8997 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8998 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8999 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
9000 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
9001 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
9002 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
9003 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
9004 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
9005 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
9006 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9007 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9008 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9009 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9010 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9011 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
9012 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
9013 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
9014 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
9015 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
9016 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
9017
9018
9019 static expression_t *parse_subexpression(precedence_t precedence)
9020 {
9021         if (token.type < 0) {
9022                 return expected_expression_error();
9023         }
9024
9025         expression_parser_function_t *parser
9026                 = &expression_parsers[token.type];
9027         source_position_t             source_position = token.source_position;
9028         expression_t                 *left;
9029
9030         if (parser->parser != NULL) {
9031                 left = parser->parser();
9032         } else {
9033                 left = parse_primary_expression();
9034         }
9035         assert(left != NULL);
9036         left->base.source_position = source_position;
9037
9038         while (true) {
9039                 if (token.type < 0) {
9040                         return expected_expression_error();
9041                 }
9042
9043                 parser = &expression_parsers[token.type];
9044                 if (parser->infix_parser == NULL)
9045                         break;
9046                 if (parser->infix_precedence < precedence)
9047                         break;
9048
9049                 left = parser->infix_parser(left);
9050
9051                 assert(left != NULL);
9052                 assert(left->kind != EXPR_UNKNOWN);
9053                 left->base.source_position = source_position;
9054         }
9055
9056         return left;
9057 }
9058
9059 /**
9060  * Parse an expression.
9061  */
9062 static expression_t *parse_expression(void)
9063 {
9064         return parse_subexpression(PREC_EXPRESSION);
9065 }
9066
9067 /**
9068  * Register a parser for a prefix-like operator.
9069  *
9070  * @param parser      the parser function
9071  * @param token_type  the token type of the prefix token
9072  */
9073 static void register_expression_parser(parse_expression_function parser,
9074                                        int token_type)
9075 {
9076         expression_parser_function_t *entry = &expression_parsers[token_type];
9077
9078         if (entry->parser != NULL) {
9079                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9080                 panic("trying to register multiple expression parsers for a token");
9081         }
9082         entry->parser = parser;
9083 }
9084
9085 /**
9086  * Register a parser for an infix operator with given precedence.
9087  *
9088  * @param parser      the parser function
9089  * @param token_type  the token type of the infix operator
9090  * @param precedence  the precedence of the operator
9091  */
9092 static void register_infix_parser(parse_expression_infix_function parser,
9093                                   int token_type, precedence_t precedence)
9094 {
9095         expression_parser_function_t *entry = &expression_parsers[token_type];
9096
9097         if (entry->infix_parser != NULL) {
9098                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9099                 panic("trying to register multiple infix expression parsers for a "
9100                       "token");
9101         }
9102         entry->infix_parser     = parser;
9103         entry->infix_precedence = precedence;
9104 }
9105
9106 /**
9107  * Initialize the expression parsers.
9108  */
9109 static void init_expression_parsers(void)
9110 {
9111         memset(&expression_parsers, 0, sizeof(expression_parsers));
9112
9113         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9114         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9115         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9116         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9117         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9118         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9119         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9120         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9121         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9122         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9123         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9124         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9125         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9126         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9127         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9128         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9129         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9130         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9131         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9132         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9133         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9134         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9135         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9136         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9137         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9138         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9139         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9140         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9141         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9142         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9143         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9144         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9145         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9146         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9147         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9148         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9149         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9150
9151         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9152         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9153         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9154         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9155         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9156         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9157         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9158         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9159         register_expression_parser(parse_sizeof,                      T_sizeof);
9160         register_expression_parser(parse_alignof,                     T___alignof__);
9161         register_expression_parser(parse_extension,                   T___extension__);
9162         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9163         register_expression_parser(parse_delete,                      T_delete);
9164         register_expression_parser(parse_throw,                       T_throw);
9165 }
9166
9167 /**
9168  * Parse a asm statement arguments specification.
9169  */
9170 static asm_argument_t *parse_asm_arguments(bool is_out)
9171 {
9172         asm_argument_t  *result = NULL;
9173         asm_argument_t **anchor = &result;
9174
9175         while (token.type == T_STRING_LITERAL || token.type == '[') {
9176                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9177                 memset(argument, 0, sizeof(argument[0]));
9178
9179                 if (next_if('[')) {
9180                         if (token.type != T_IDENTIFIER) {
9181                                 parse_error_expected("while parsing asm argument",
9182                                                      T_IDENTIFIER, NULL);
9183                                 return NULL;
9184                         }
9185                         argument->symbol = token.symbol;
9186
9187                         expect(']', end_error);
9188                 }
9189
9190                 argument->constraints = parse_string_literals();
9191                 expect('(', end_error);
9192                 add_anchor_token(')');
9193                 expression_t *expression = parse_expression();
9194                 rem_anchor_token(')');
9195                 if (is_out) {
9196                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9197                          * change size or type representation (e.g. int -> long is ok, but
9198                          * int -> float is not) */
9199                         if (expression->kind == EXPR_UNARY_CAST) {
9200                                 type_t      *const type = expression->base.type;
9201                                 type_kind_t  const kind = type->kind;
9202                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9203                                         unsigned flags;
9204                                         unsigned size;
9205                                         if (kind == TYPE_ATOMIC) {
9206                                                 atomic_type_kind_t const akind = type->atomic.akind;
9207                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9208                                                 size  = get_atomic_type_size(akind);
9209                                         } else {
9210                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9211                                                 size  = get_atomic_type_size(get_intptr_kind());
9212                                         }
9213
9214                                         do {
9215                                                 expression_t *const value      = expression->unary.value;
9216                                                 type_t       *const value_type = value->base.type;
9217                                                 type_kind_t   const value_kind = value_type->kind;
9218
9219                                                 unsigned value_flags;
9220                                                 unsigned value_size;
9221                                                 if (value_kind == TYPE_ATOMIC) {
9222                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9223                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9224                                                         value_size  = get_atomic_type_size(value_akind);
9225                                                 } else if (value_kind == TYPE_POINTER) {
9226                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9227                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9228                                                 } else {
9229                                                         break;
9230                                                 }
9231
9232                                                 if (value_flags != flags || value_size != size)
9233                                                         break;
9234
9235                                                 expression = value;
9236                                         } while (expression->kind == EXPR_UNARY_CAST);
9237                                 }
9238                         }
9239
9240                         if (!is_lvalue(expression)) {
9241                                 errorf(&expression->base.source_position,
9242                                        "asm output argument is not an lvalue");
9243                         }
9244
9245                         if (argument->constraints.begin[0] == '=')
9246                                 determine_lhs_ent(expression, NULL);
9247                         else
9248                                 mark_vars_read(expression, NULL);
9249                 } else {
9250                         mark_vars_read(expression, NULL);
9251                 }
9252                 argument->expression = expression;
9253                 expect(')', end_error);
9254
9255                 set_address_taken(expression, true);
9256
9257                 *anchor = argument;
9258                 anchor  = &argument->next;
9259
9260                 if (!next_if(','))
9261                         break;
9262         }
9263
9264         return result;
9265 end_error:
9266         return NULL;
9267 }
9268
9269 /**
9270  * Parse a asm statement clobber specification.
9271  */
9272 static asm_clobber_t *parse_asm_clobbers(void)
9273 {
9274         asm_clobber_t *result  = NULL;
9275         asm_clobber_t **anchor = &result;
9276
9277         while (token.type == T_STRING_LITERAL) {
9278                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9279                 clobber->clobber       = parse_string_literals();
9280
9281                 *anchor = clobber;
9282                 anchor  = &clobber->next;
9283
9284                 if (!next_if(','))
9285                         break;
9286         }
9287
9288         return result;
9289 }
9290
9291 /**
9292  * Parse an asm statement.
9293  */
9294 static statement_t *parse_asm_statement(void)
9295 {
9296         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9297         asm_statement_t *asm_statement = &statement->asms;
9298
9299         eat(T_asm);
9300
9301         if (next_if(T_volatile))
9302                 asm_statement->is_volatile = true;
9303
9304         expect('(', end_error);
9305         add_anchor_token(')');
9306         if (token.type != T_STRING_LITERAL) {
9307                 parse_error_expected("after asm(", T_STRING_LITERAL, NULL);
9308                 goto end_of_asm;
9309         }
9310         asm_statement->asm_text = parse_string_literals();
9311
9312         add_anchor_token(':');
9313         if (!next_if(':')) {
9314                 rem_anchor_token(':');
9315                 goto end_of_asm;
9316         }
9317
9318         asm_statement->outputs = parse_asm_arguments(true);
9319         if (!next_if(':')) {
9320                 rem_anchor_token(':');
9321                 goto end_of_asm;
9322         }
9323
9324         asm_statement->inputs = parse_asm_arguments(false);
9325         if (!next_if(':')) {
9326                 rem_anchor_token(':');
9327                 goto end_of_asm;
9328         }
9329         rem_anchor_token(':');
9330
9331         asm_statement->clobbers = parse_asm_clobbers();
9332
9333 end_of_asm:
9334         rem_anchor_token(')');
9335         expect(')', end_error);
9336         expect(';', end_error);
9337
9338         if (asm_statement->outputs == NULL) {
9339                 /* GCC: An 'asm' instruction without any output operands will be treated
9340                  * identically to a volatile 'asm' instruction. */
9341                 asm_statement->is_volatile = true;
9342         }
9343
9344         return statement;
9345 end_error:
9346         return create_invalid_statement();
9347 }
9348
9349 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
9350 {
9351         statement_t *inner_stmt;
9352         switch (token.type) {
9353                 case '}':
9354                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
9355                         inner_stmt = create_invalid_statement();
9356                         break;
9357
9358                 case ';':
9359                         if (label->kind == STATEMENT_LABEL) {
9360                                 /* Eat an empty statement here, to avoid the warning about an empty
9361                                  * statement after a label.  label:; is commonly used to have a label
9362                                  * before a closing brace. */
9363                                 inner_stmt = create_empty_statement();
9364                                 next_token();
9365                                 break;
9366                         }
9367                         /* FALLTHROUGH */
9368
9369                 default:
9370                         inner_stmt = parse_statement();
9371                         /* ISO/IEC 14882:1998(E) §6:1/§6.7  Declarations are statements */
9372                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9373                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
9374                         }
9375                         break;
9376         }
9377         return inner_stmt;
9378 }
9379
9380 /**
9381  * Parse a case statement.
9382  */
9383 static statement_t *parse_case_statement(void)
9384 {
9385         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9386         source_position_t *const pos       = &statement->base.source_position;
9387
9388         eat(T_case);
9389
9390         expression_t *const expression   = parse_expression();
9391         statement->case_label.expression = expression;
9392         expression_classification_t const expr_class = is_constant_expression(expression);
9393         if (expr_class != EXPR_CLASS_CONSTANT) {
9394                 if (expr_class != EXPR_CLASS_ERROR) {
9395                         errorf(pos, "case label does not reduce to an integer constant");
9396                 }
9397                 statement->case_label.is_bad = true;
9398         } else {
9399                 long const val = fold_constant_to_int(expression);
9400                 statement->case_label.first_case = val;
9401                 statement->case_label.last_case  = val;
9402         }
9403
9404         if (GNU_MODE) {
9405                 if (next_if(T_DOTDOTDOT)) {
9406                         expression_t *const end_range   = parse_expression();
9407                         statement->case_label.end_range = end_range;
9408                         expression_classification_t const end_class = is_constant_expression(end_range);
9409                         if (end_class != EXPR_CLASS_CONSTANT) {
9410                                 if (end_class != EXPR_CLASS_ERROR) {
9411                                         errorf(pos, "case range does not reduce to an integer constant");
9412                                 }
9413                                 statement->case_label.is_bad = true;
9414                         } else {
9415                                 long const val = fold_constant_to_int(end_range);
9416                                 statement->case_label.last_case = val;
9417
9418                                 if (warning.other && val < statement->case_label.first_case) {
9419                                         statement->case_label.is_empty_range = true;
9420                                         warningf(pos, "empty range specified");
9421                                 }
9422                         }
9423                 }
9424         }
9425
9426         PUSH_PARENT(statement);
9427
9428         expect(':', end_error);
9429 end_error:
9430
9431         if (current_switch != NULL) {
9432                 if (! statement->case_label.is_bad) {
9433                         /* Check for duplicate case values */
9434                         case_label_statement_t *c = &statement->case_label;
9435                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9436                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9437                                         continue;
9438
9439                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9440                                         continue;
9441
9442                                 errorf(pos, "duplicate case value (previously used %P)",
9443                                        &l->base.source_position);
9444                                 break;
9445                         }
9446                 }
9447                 /* link all cases into the switch statement */
9448                 if (current_switch->last_case == NULL) {
9449                         current_switch->first_case      = &statement->case_label;
9450                 } else {
9451                         current_switch->last_case->next = &statement->case_label;
9452                 }
9453                 current_switch->last_case = &statement->case_label;
9454         } else {
9455                 errorf(pos, "case label not within a switch statement");
9456         }
9457
9458         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
9459
9460         POP_PARENT;
9461         return statement;
9462 }
9463
9464 /**
9465  * Parse a default statement.
9466  */
9467 static statement_t *parse_default_statement(void)
9468 {
9469         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9470
9471         eat(T_default);
9472
9473         PUSH_PARENT(statement);
9474
9475         expect(':', end_error);
9476 end_error:
9477
9478         if (current_switch != NULL) {
9479                 const case_label_statement_t *def_label = current_switch->default_label;
9480                 if (def_label != NULL) {
9481                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9482                                &def_label->base.source_position);
9483                 } else {
9484                         current_switch->default_label = &statement->case_label;
9485
9486                         /* link all cases into the switch statement */
9487                         if (current_switch->last_case == NULL) {
9488                                 current_switch->first_case      = &statement->case_label;
9489                         } else {
9490                                 current_switch->last_case->next = &statement->case_label;
9491                         }
9492                         current_switch->last_case = &statement->case_label;
9493                 }
9494         } else {
9495                 errorf(&statement->base.source_position,
9496                         "'default' label not within a switch statement");
9497         }
9498
9499         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9500
9501         POP_PARENT;
9502         return statement;
9503 }
9504
9505 /**
9506  * Parse a label statement.
9507  */
9508 static statement_t *parse_label_statement(void)
9509 {
9510         assert(token.type == T_IDENTIFIER);
9511         symbol_t *symbol = token.symbol;
9512         label_t  *label  = get_label(symbol);
9513
9514         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9515         statement->label.label       = label;
9516
9517         next_token();
9518
9519         PUSH_PARENT(statement);
9520
9521         /* if statement is already set then the label is defined twice,
9522          * otherwise it was just mentioned in a goto/local label declaration so far
9523          */
9524         if (label->statement != NULL) {
9525                 errorf(HERE, "duplicate label '%Y' (declared %P)",
9526                        symbol, &label->base.source_position);
9527         } else {
9528                 label->base.source_position = token.source_position;
9529                 label->statement            = statement;
9530         }
9531
9532         eat(':');
9533
9534         statement->label.statement = parse_label_inner_statement(statement, "label");
9535
9536         /* remember the labels in a list for later checking */
9537         *label_anchor = &statement->label;
9538         label_anchor  = &statement->label.next;
9539
9540         POP_PARENT;
9541         return statement;
9542 }
9543
9544 /**
9545  * Parse an if statement.
9546  */
9547 static statement_t *parse_if(void)
9548 {
9549         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9550
9551         eat(T_if);
9552
9553         PUSH_PARENT(statement);
9554
9555         add_anchor_token('{');
9556
9557         expect('(', end_error);
9558         add_anchor_token(')');
9559         expression_t *const expr = parse_expression();
9560         statement->ifs.condition = expr;
9561         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9562          *             scalar type. */
9563         semantic_condition(expr, "condition of 'if'-statment");
9564         mark_vars_read(expr, NULL);
9565         rem_anchor_token(')');
9566         expect(')', end_error);
9567
9568 end_error:
9569         rem_anchor_token('{');
9570
9571         add_anchor_token(T_else);
9572         statement_t *const true_stmt = parse_statement();
9573         statement->ifs.true_statement = true_stmt;
9574         rem_anchor_token(T_else);
9575
9576         if (next_if(T_else)) {
9577                 statement->ifs.false_statement = parse_statement();
9578         } else if (warning.parentheses &&
9579                         true_stmt->kind == STATEMENT_IF &&
9580                         true_stmt->ifs.false_statement != NULL) {
9581                 warningf(&true_stmt->base.source_position,
9582                                 "suggest explicit braces to avoid ambiguous 'else'");
9583         }
9584
9585         POP_PARENT;
9586         return statement;
9587 }
9588
9589 /**
9590  * Check that all enums are handled in a switch.
9591  *
9592  * @param statement  the switch statement to check
9593  */
9594 static void check_enum_cases(const switch_statement_t *statement)
9595 {
9596         const type_t *type = skip_typeref(statement->expression->base.type);
9597         if (! is_type_enum(type))
9598                 return;
9599         const enum_type_t *enumt = &type->enumt;
9600
9601         /* if we have a default, no warnings */
9602         if (statement->default_label != NULL)
9603                 return;
9604
9605         /* FIXME: calculation of value should be done while parsing */
9606         /* TODO: quadratic algorithm here. Change to an n log n one */
9607         long            last_value = -1;
9608         const entity_t *entry      = enumt->enume->base.next;
9609         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9610              entry = entry->base.next) {
9611                 const expression_t *expression = entry->enum_value.value;
9612                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9613                 bool                found      = false;
9614                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9615                         if (l->expression == NULL)
9616                                 continue;
9617                         if (l->first_case <= value && value <= l->last_case) {
9618                                 found = true;
9619                                 break;
9620                         }
9621                 }
9622                 if (! found) {
9623                         warningf(&statement->base.source_position,
9624                                  "enumeration value '%Y' not handled in switch",
9625                                  entry->base.symbol);
9626                 }
9627                 last_value = value;
9628         }
9629 }
9630
9631 /**
9632  * Parse a switch statement.
9633  */
9634 static statement_t *parse_switch(void)
9635 {
9636         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9637
9638         eat(T_switch);
9639
9640         PUSH_PARENT(statement);
9641
9642         expect('(', end_error);
9643         add_anchor_token(')');
9644         expression_t *const expr = parse_expression();
9645         mark_vars_read(expr, NULL);
9646         type_t       *      type = skip_typeref(expr->base.type);
9647         if (is_type_integer(type)) {
9648                 type = promote_integer(type);
9649                 if (warning.traditional) {
9650                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9651                                 warningf(&expr->base.source_position,
9652                                         "'%T' switch expression not converted to '%T' in ISO C",
9653                                         type, type_int);
9654                         }
9655                 }
9656         } else if (is_type_valid(type)) {
9657                 errorf(&expr->base.source_position,
9658                        "switch quantity is not an integer, but '%T'", type);
9659                 type = type_error_type;
9660         }
9661         statement->switchs.expression = create_implicit_cast(expr, type);
9662         expect(')', end_error);
9663         rem_anchor_token(')');
9664
9665         switch_statement_t *rem = current_switch;
9666         current_switch          = &statement->switchs;
9667         statement->switchs.body = parse_statement();
9668         current_switch          = rem;
9669
9670         if (warning.switch_default &&
9671             statement->switchs.default_label == NULL) {
9672                 warningf(&statement->base.source_position, "switch has no default case");
9673         }
9674         if (warning.switch_enum)
9675                 check_enum_cases(&statement->switchs);
9676
9677         POP_PARENT;
9678         return statement;
9679 end_error:
9680         POP_PARENT;
9681         return create_invalid_statement();
9682 }
9683
9684 static statement_t *parse_loop_body(statement_t *const loop)
9685 {
9686         statement_t *const rem = current_loop;
9687         current_loop = loop;
9688
9689         statement_t *const body = parse_statement();
9690
9691         current_loop = rem;
9692         return body;
9693 }
9694
9695 /**
9696  * Parse a while statement.
9697  */
9698 static statement_t *parse_while(void)
9699 {
9700         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9701
9702         eat(T_while);
9703
9704         PUSH_PARENT(statement);
9705
9706         expect('(', end_error);
9707         add_anchor_token(')');
9708         expression_t *const cond = parse_expression();
9709         statement->whiles.condition = cond;
9710         /* §6.8.5:2    The controlling expression of an iteration statement shall
9711          *             have scalar type. */
9712         semantic_condition(cond, "condition of 'while'-statement");
9713         mark_vars_read(cond, NULL);
9714         rem_anchor_token(')');
9715         expect(')', end_error);
9716
9717         statement->whiles.body = parse_loop_body(statement);
9718
9719         POP_PARENT;
9720         return statement;
9721 end_error:
9722         POP_PARENT;
9723         return create_invalid_statement();
9724 }
9725
9726 /**
9727  * Parse a do statement.
9728  */
9729 static statement_t *parse_do(void)
9730 {
9731         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9732
9733         eat(T_do);
9734
9735         PUSH_PARENT(statement);
9736
9737         add_anchor_token(T_while);
9738         statement->do_while.body = parse_loop_body(statement);
9739         rem_anchor_token(T_while);
9740
9741         expect(T_while, end_error);
9742         expect('(', end_error);
9743         add_anchor_token(')');
9744         expression_t *const cond = parse_expression();
9745         statement->do_while.condition = cond;
9746         /* §6.8.5:2    The controlling expression of an iteration statement shall
9747          *             have scalar type. */
9748         semantic_condition(cond, "condition of 'do-while'-statement");
9749         mark_vars_read(cond, NULL);
9750         rem_anchor_token(')');
9751         expect(')', end_error);
9752         expect(';', end_error);
9753
9754         POP_PARENT;
9755         return statement;
9756 end_error:
9757         POP_PARENT;
9758         return create_invalid_statement();
9759 }
9760
9761 /**
9762  * Parse a for statement.
9763  */
9764 static statement_t *parse_for(void)
9765 {
9766         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9767
9768         eat(T_for);
9769
9770         expect('(', end_error1);
9771         add_anchor_token(')');
9772
9773         PUSH_PARENT(statement);
9774
9775         size_t const  top       = environment_top();
9776         scope_t      *old_scope = scope_push(&statement->fors.scope);
9777
9778         bool old_gcc_extension = in_gcc_extension;
9779         while (next_if(T___extension__)) {
9780                 in_gcc_extension = true;
9781         }
9782
9783         if (next_if(';')) {
9784         } else if (is_declaration_specifier(&token, false)) {
9785                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9786         } else {
9787                 add_anchor_token(';');
9788                 expression_t *const init = parse_expression();
9789                 statement->fors.initialisation = init;
9790                 mark_vars_read(init, ENT_ANY);
9791                 if (warning.unused_value && !expression_has_effect(init)) {
9792                         warningf(&init->base.source_position,
9793                                         "initialisation of 'for'-statement has no effect");
9794                 }
9795                 rem_anchor_token(';');
9796                 expect(';', end_error2);
9797         }
9798         in_gcc_extension = old_gcc_extension;
9799
9800         if (token.type != ';') {
9801                 add_anchor_token(';');
9802                 expression_t *const cond = parse_expression();
9803                 statement->fors.condition = cond;
9804                 /* §6.8.5:2    The controlling expression of an iteration statement
9805                  *             shall have scalar type. */
9806                 semantic_condition(cond, "condition of 'for'-statement");
9807                 mark_vars_read(cond, NULL);
9808                 rem_anchor_token(';');
9809         }
9810         expect(';', end_error2);
9811         if (token.type != ')') {
9812                 expression_t *const step = parse_expression();
9813                 statement->fors.step = step;
9814                 mark_vars_read(step, ENT_ANY);
9815                 if (warning.unused_value && !expression_has_effect(step)) {
9816                         warningf(&step->base.source_position,
9817                                  "step of 'for'-statement has no effect");
9818                 }
9819         }
9820         expect(')', end_error2);
9821         rem_anchor_token(')');
9822         statement->fors.body = parse_loop_body(statement);
9823
9824         assert(current_scope == &statement->fors.scope);
9825         scope_pop(old_scope);
9826         environment_pop_to(top);
9827
9828         POP_PARENT;
9829         return statement;
9830
9831 end_error2:
9832         POP_PARENT;
9833         rem_anchor_token(')');
9834         assert(current_scope == &statement->fors.scope);
9835         scope_pop(old_scope);
9836         environment_pop_to(top);
9837         /* fallthrough */
9838
9839 end_error1:
9840         return create_invalid_statement();
9841 }
9842
9843 /**
9844  * Parse a goto statement.
9845  */
9846 static statement_t *parse_goto(void)
9847 {
9848         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
9849         eat(T_goto);
9850
9851         if (GNU_MODE && next_if('*')) {
9852                 expression_t *expression = parse_expression();
9853                 mark_vars_read(expression, NULL);
9854
9855                 /* Argh: although documentation says the expression must be of type void*,
9856                  * gcc accepts anything that can be casted into void* without error */
9857                 type_t *type = expression->base.type;
9858
9859                 if (type != type_error_type) {
9860                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9861                                 errorf(&expression->base.source_position,
9862                                         "cannot convert to a pointer type");
9863                         } else if (warning.other && type != type_void_ptr) {
9864                                 warningf(&expression->base.source_position,
9865                                         "type of computed goto expression should be 'void*' not '%T'", type);
9866                         }
9867                         expression = create_implicit_cast(expression, type_void_ptr);
9868                 }
9869
9870                 statement->gotos.expression = expression;
9871         } else if (token.type == T_IDENTIFIER) {
9872                 symbol_t *symbol = token.symbol;
9873                 next_token();
9874                 statement->gotos.label = get_label(symbol);
9875         } else {
9876                 if (GNU_MODE)
9877                         parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9878                 else
9879                         parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9880                 eat_until_anchor();
9881                 return create_invalid_statement();
9882         }
9883
9884         /* remember the goto's in a list for later checking */
9885         *goto_anchor = &statement->gotos;
9886         goto_anchor  = &statement->gotos.next;
9887
9888         expect(';', end_error);
9889
9890 end_error:
9891         return statement;
9892 }
9893
9894 /**
9895  * Parse a continue statement.
9896  */
9897 static statement_t *parse_continue(void)
9898 {
9899         if (current_loop == NULL) {
9900                 errorf(HERE, "continue statement not within loop");
9901         }
9902
9903         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9904
9905         eat(T_continue);
9906         expect(';', end_error);
9907
9908 end_error:
9909         return statement;
9910 }
9911
9912 /**
9913  * Parse a break statement.
9914  */
9915 static statement_t *parse_break(void)
9916 {
9917         if (current_switch == NULL && current_loop == NULL) {
9918                 errorf(HERE, "break statement not within loop or switch");
9919         }
9920
9921         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9922
9923         eat(T_break);
9924         expect(';', end_error);
9925
9926 end_error:
9927         return statement;
9928 }
9929
9930 /**
9931  * Parse a __leave statement.
9932  */
9933 static statement_t *parse_leave_statement(void)
9934 {
9935         if (current_try == NULL) {
9936                 errorf(HERE, "__leave statement not within __try");
9937         }
9938
9939         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9940
9941         eat(T___leave);
9942         expect(';', end_error);
9943
9944 end_error:
9945         return statement;
9946 }
9947
9948 /**
9949  * Check if a given entity represents a local variable.
9950  */
9951 static bool is_local_variable(const entity_t *entity)
9952 {
9953         if (entity->kind != ENTITY_VARIABLE)
9954                 return false;
9955
9956         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9957         case STORAGE_CLASS_AUTO:
9958         case STORAGE_CLASS_REGISTER: {
9959                 const type_t *type = skip_typeref(entity->declaration.type);
9960                 if (is_type_function(type)) {
9961                         return false;
9962                 } else {
9963                         return true;
9964                 }
9965         }
9966         default:
9967                 return false;
9968         }
9969 }
9970
9971 /**
9972  * Check if a given expression represents a local variable.
9973  */
9974 static bool expression_is_local_variable(const expression_t *expression)
9975 {
9976         if (expression->base.kind != EXPR_REFERENCE) {
9977                 return false;
9978         }
9979         const entity_t *entity = expression->reference.entity;
9980         return is_local_variable(entity);
9981 }
9982
9983 /**
9984  * Check if a given expression represents a local variable and
9985  * return its declaration then, else return NULL.
9986  */
9987 entity_t *expression_is_variable(const expression_t *expression)
9988 {
9989         if (expression->base.kind != EXPR_REFERENCE) {
9990                 return NULL;
9991         }
9992         entity_t *entity = expression->reference.entity;
9993         if (entity->kind != ENTITY_VARIABLE)
9994                 return NULL;
9995
9996         return entity;
9997 }
9998
9999 /**
10000  * Parse a return statement.
10001  */
10002 static statement_t *parse_return(void)
10003 {
10004         eat(T_return);
10005
10006         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
10007
10008         expression_t *return_value = NULL;
10009         if (token.type != ';') {
10010                 return_value = parse_expression();
10011                 mark_vars_read(return_value, NULL);
10012         }
10013
10014         const type_t *const func_type = skip_typeref(current_function->base.type);
10015         assert(is_type_function(func_type));
10016         type_t *const return_type = skip_typeref(func_type->function.return_type);
10017
10018         source_position_t const *const pos = &statement->base.source_position;
10019         if (return_value != NULL) {
10020                 type_t *return_value_type = skip_typeref(return_value->base.type);
10021
10022                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10023                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10024                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
10025                                 /* Only warn in C mode, because GCC does the same */
10026                                 if (c_mode & _CXX || strict_mode) {
10027                                         errorf(pos,
10028                                                         "'return' with a value, in function returning 'void'");
10029                                 } else if (warning.other) {
10030                                         warningf(pos,
10031                                                         "'return' with a value, in function returning 'void'");
10032                                 }
10033                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10034                                 /* Only warn in C mode, because GCC does the same */
10035                                 if (strict_mode) {
10036                                         errorf(pos,
10037                                                         "'return' with expression in function returning 'void'");
10038                                 } else if (warning.other) {
10039                                         warningf(pos,
10040                                                         "'return' with expression in function returning 'void'");
10041                                 }
10042                         }
10043                 } else {
10044                         assign_error_t error = semantic_assign(return_type, return_value);
10045                         report_assign_error(error, return_type, return_value, "'return'",
10046                                             pos);
10047                 }
10048                 return_value = create_implicit_cast(return_value, return_type);
10049                 /* check for returning address of a local var */
10050                 if (warning.other && return_value != NULL
10051                     && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10052                         const expression_t *expression = return_value->unary.value;
10053                         if (expression_is_local_variable(expression)) {
10054                                 warningf(pos, "function returns address of local variable");
10055                         }
10056                 }
10057         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10058                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10059                 if (c_mode & _CXX || strict_mode) {
10060                         errorf(pos,
10061                                "'return' without value, in function returning non-void");
10062                 } else {
10063                         warningf(pos,
10064                                  "'return' without value, in function returning non-void");
10065                 }
10066         }
10067         statement->returns.value = return_value;
10068
10069         expect(';', end_error);
10070
10071 end_error:
10072         return statement;
10073 }
10074
10075 /**
10076  * Parse a declaration statement.
10077  */
10078 static statement_t *parse_declaration_statement(void)
10079 {
10080         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10081
10082         entity_t *before = current_scope->last_entity;
10083         if (GNU_MODE) {
10084                 parse_external_declaration();
10085         } else {
10086                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10087         }
10088
10089         declaration_statement_t *const decl  = &statement->declaration;
10090         entity_t                *const begin =
10091                 before != NULL ? before->base.next : current_scope->entities;
10092         decl->declarations_begin = begin;
10093         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
10094
10095         return statement;
10096 }
10097
10098 /**
10099  * Parse an expression statement, ie. expr ';'.
10100  */
10101 static statement_t *parse_expression_statement(void)
10102 {
10103         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10104
10105         expression_t *const expr         = parse_expression();
10106         statement->expression.expression = expr;
10107         mark_vars_read(expr, ENT_ANY);
10108
10109         expect(';', end_error);
10110
10111 end_error:
10112         return statement;
10113 }
10114
10115 /**
10116  * Parse a microsoft __try { } __finally { } or
10117  * __try{ } __except() { }
10118  */
10119 static statement_t *parse_ms_try_statment(void)
10120 {
10121         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10122         eat(T___try);
10123
10124         PUSH_PARENT(statement);
10125
10126         ms_try_statement_t *rem = current_try;
10127         current_try = &statement->ms_try;
10128         statement->ms_try.try_statement = parse_compound_statement(false);
10129         current_try = rem;
10130
10131         POP_PARENT;
10132
10133         if (next_if(T___except)) {
10134                 expect('(', end_error);
10135                 add_anchor_token(')');
10136                 expression_t *const expr = parse_expression();
10137                 mark_vars_read(expr, NULL);
10138                 type_t       *      type = skip_typeref(expr->base.type);
10139                 if (is_type_integer(type)) {
10140                         type = promote_integer(type);
10141                 } else if (is_type_valid(type)) {
10142                         errorf(&expr->base.source_position,
10143                                "__expect expression is not an integer, but '%T'", type);
10144                         type = type_error_type;
10145                 }
10146                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10147                 rem_anchor_token(')');
10148                 expect(')', end_error);
10149                 statement->ms_try.final_statement = parse_compound_statement(false);
10150         } else if (next_if(T__finally)) {
10151                 statement->ms_try.final_statement = parse_compound_statement(false);
10152         } else {
10153                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10154                 return create_invalid_statement();
10155         }
10156         return statement;
10157 end_error:
10158         return create_invalid_statement();
10159 }
10160
10161 static statement_t *parse_empty_statement(void)
10162 {
10163         if (warning.empty_statement) {
10164                 warningf(HERE, "statement is empty");
10165         }
10166         statement_t *const statement = create_empty_statement();
10167         eat(';');
10168         return statement;
10169 }
10170
10171 static statement_t *parse_local_label_declaration(void)
10172 {
10173         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10174
10175         eat(T___label__);
10176
10177         entity_t *begin   = NULL;
10178         entity_t *end     = NULL;
10179         entity_t **anchor = &begin;
10180         do {
10181                 if (token.type != T_IDENTIFIER) {
10182                         parse_error_expected("while parsing local label declaration",
10183                                 T_IDENTIFIER, NULL);
10184                         goto end_error;
10185                 }
10186                 symbol_t *symbol = token.symbol;
10187                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10188                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10189                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10190                                symbol, &entity->base.source_position);
10191                 } else {
10192                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10193
10194                         entity->base.parent_scope    = current_scope;
10195                         entity->base.namespc         = NAMESPACE_LABEL;
10196                         entity->base.source_position = token.source_position;
10197                         entity->base.symbol          = symbol;
10198
10199                         *anchor = entity;
10200                         anchor  = &entity->base.next;
10201                         end     = entity;
10202
10203                         environment_push(entity);
10204                 }
10205                 next_token();
10206         } while (next_if(','));
10207         expect(';', end_error);
10208 end_error:
10209         statement->declaration.declarations_begin = begin;
10210         statement->declaration.declarations_end   = end;
10211         return statement;
10212 }
10213
10214 static void parse_namespace_definition(void)
10215 {
10216         eat(T_namespace);
10217
10218         entity_t *entity = NULL;
10219         symbol_t *symbol = NULL;
10220
10221         if (token.type == T_IDENTIFIER) {
10222                 symbol = token.symbol;
10223                 next_token();
10224
10225                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10226                 if (entity != NULL
10227                                 && entity->kind != ENTITY_NAMESPACE
10228                                 && entity->base.parent_scope == current_scope) {
10229                         if (is_entity_valid(entity)) {
10230                                 error_redefined_as_different_kind(&token.source_position,
10231                                                 entity, ENTITY_NAMESPACE);
10232                         }
10233                         entity = NULL;
10234                 }
10235         }
10236
10237         if (entity == NULL) {
10238                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10239                 entity->base.symbol          = symbol;
10240                 entity->base.source_position = token.source_position;
10241                 entity->base.namespc         = NAMESPACE_NORMAL;
10242                 entity->base.parent_scope    = current_scope;
10243         }
10244
10245         if (token.type == '=') {
10246                 /* TODO: parse namespace alias */
10247                 panic("namespace alias definition not supported yet");
10248         }
10249
10250         environment_push(entity);
10251         append_entity(current_scope, entity);
10252
10253         size_t const  top       = environment_top();
10254         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10255
10256         entity_t     *old_current_entity = current_entity;
10257         current_entity = entity;
10258
10259         expect('{', end_error);
10260         parse_externals();
10261         expect('}', end_error);
10262
10263 end_error:
10264         assert(current_scope == &entity->namespacee.members);
10265         assert(current_entity == entity);
10266         current_entity = old_current_entity;
10267         scope_pop(old_scope);
10268         environment_pop_to(top);
10269 }
10270
10271 /**
10272  * Parse a statement.
10273  * There's also parse_statement() which additionally checks for
10274  * "statement has no effect" warnings
10275  */
10276 static statement_t *intern_parse_statement(void)
10277 {
10278         statement_t *statement = NULL;
10279
10280         /* declaration or statement */
10281         add_anchor_token(';');
10282         switch (token.type) {
10283         case T_IDENTIFIER: {
10284                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10285                 if (la1_type == ':') {
10286                         statement = parse_label_statement();
10287                 } else if (is_typedef_symbol(token.symbol)) {
10288                         statement = parse_declaration_statement();
10289                 } else {
10290                         /* it's an identifier, the grammar says this must be an
10291                          * expression statement. However it is common that users mistype
10292                          * declaration types, so we guess a bit here to improve robustness
10293                          * for incorrect programs */
10294                         switch (la1_type) {
10295                         case '&':
10296                         case '*':
10297                                 if (get_entity(token.symbol, NAMESPACE_NORMAL) != NULL) {
10298                         default:
10299                                         statement = parse_expression_statement();
10300                                 } else {
10301                         DECLARATION_START
10302                         case T_IDENTIFIER:
10303                                         statement = parse_declaration_statement();
10304                                 }
10305                                 break;
10306                         }
10307                 }
10308                 break;
10309         }
10310
10311         case T___extension__:
10312                 /* This can be a prefix to a declaration or an expression statement.
10313                  * We simply eat it now and parse the rest with tail recursion. */
10314                 while (next_if(T___extension__)) {}
10315                 bool old_gcc_extension = in_gcc_extension;
10316                 in_gcc_extension       = true;
10317                 statement = intern_parse_statement();
10318                 in_gcc_extension = old_gcc_extension;
10319                 break;
10320
10321         DECLARATION_START
10322                 statement = parse_declaration_statement();
10323                 break;
10324
10325         case T___label__:
10326                 statement = parse_local_label_declaration();
10327                 break;
10328
10329         case ';':         statement = parse_empty_statement();         break;
10330         case '{':         statement = parse_compound_statement(false); break;
10331         case T___leave:   statement = parse_leave_statement();         break;
10332         case T___try:     statement = parse_ms_try_statment();         break;
10333         case T_asm:       statement = parse_asm_statement();           break;
10334         case T_break:     statement = parse_break();                   break;
10335         case T_case:      statement = parse_case_statement();          break;
10336         case T_continue:  statement = parse_continue();                break;
10337         case T_default:   statement = parse_default_statement();       break;
10338         case T_do:        statement = parse_do();                      break;
10339         case T_for:       statement = parse_for();                     break;
10340         case T_goto:      statement = parse_goto();                    break;
10341         case T_if:        statement = parse_if();                      break;
10342         case T_return:    statement = parse_return();                  break;
10343         case T_switch:    statement = parse_switch();                  break;
10344         case T_while:     statement = parse_while();                   break;
10345
10346         EXPRESSION_START
10347                 statement = parse_expression_statement();
10348                 break;
10349
10350         default:
10351                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10352                 statement = create_invalid_statement();
10353                 if (!at_anchor())
10354                         next_token();
10355                 break;
10356         }
10357         rem_anchor_token(';');
10358
10359         assert(statement != NULL
10360                         && statement->base.source_position.input_name != NULL);
10361
10362         return statement;
10363 }
10364
10365 /**
10366  * parse a statement and emits "statement has no effect" warning if needed
10367  * (This is really a wrapper around intern_parse_statement with check for 1
10368  *  single warning. It is needed, because for statement expressions we have
10369  *  to avoid the warning on the last statement)
10370  */
10371 static statement_t *parse_statement(void)
10372 {
10373         statement_t *statement = intern_parse_statement();
10374
10375         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10376                 expression_t *expression = statement->expression.expression;
10377                 if (!expression_has_effect(expression)) {
10378                         warningf(&expression->base.source_position,
10379                                         "statement has no effect");
10380                 }
10381         }
10382
10383         return statement;
10384 }
10385
10386 /**
10387  * Parse a compound statement.
10388  */
10389 static statement_t *parse_compound_statement(bool inside_expression_statement)
10390 {
10391         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10392
10393         PUSH_PARENT(statement);
10394
10395         eat('{');
10396         add_anchor_token('}');
10397         /* tokens, which can start a statement */
10398         /* TODO MS, __builtin_FOO */
10399         add_anchor_token('!');
10400         add_anchor_token('&');
10401         add_anchor_token('(');
10402         add_anchor_token('*');
10403         add_anchor_token('+');
10404         add_anchor_token('-');
10405         add_anchor_token('{');
10406         add_anchor_token('~');
10407         add_anchor_token(T_CHARACTER_CONSTANT);
10408         add_anchor_token(T_COLONCOLON);
10409         add_anchor_token(T_FLOATINGPOINT);
10410         add_anchor_token(T_IDENTIFIER);
10411         add_anchor_token(T_INTEGER);
10412         add_anchor_token(T_MINUSMINUS);
10413         add_anchor_token(T_PLUSPLUS);
10414         add_anchor_token(T_STRING_LITERAL);
10415         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10416         add_anchor_token(T_WIDE_STRING_LITERAL);
10417         add_anchor_token(T__Bool);
10418         add_anchor_token(T__Complex);
10419         add_anchor_token(T__Imaginary);
10420         add_anchor_token(T___FUNCTION__);
10421         add_anchor_token(T___PRETTY_FUNCTION__);
10422         add_anchor_token(T___alignof__);
10423         add_anchor_token(T___attribute__);
10424         add_anchor_token(T___builtin_va_start);
10425         add_anchor_token(T___extension__);
10426         add_anchor_token(T___func__);
10427         add_anchor_token(T___imag__);
10428         add_anchor_token(T___label__);
10429         add_anchor_token(T___real__);
10430         add_anchor_token(T___thread);
10431         add_anchor_token(T_asm);
10432         add_anchor_token(T_auto);
10433         add_anchor_token(T_bool);
10434         add_anchor_token(T_break);
10435         add_anchor_token(T_case);
10436         add_anchor_token(T_char);
10437         add_anchor_token(T_class);
10438         add_anchor_token(T_const);
10439         add_anchor_token(T_const_cast);
10440         add_anchor_token(T_continue);
10441         add_anchor_token(T_default);
10442         add_anchor_token(T_delete);
10443         add_anchor_token(T_double);
10444         add_anchor_token(T_do);
10445         add_anchor_token(T_dynamic_cast);
10446         add_anchor_token(T_enum);
10447         add_anchor_token(T_extern);
10448         add_anchor_token(T_false);
10449         add_anchor_token(T_float);
10450         add_anchor_token(T_for);
10451         add_anchor_token(T_goto);
10452         add_anchor_token(T_if);
10453         add_anchor_token(T_inline);
10454         add_anchor_token(T_int);
10455         add_anchor_token(T_long);
10456         add_anchor_token(T_new);
10457         add_anchor_token(T_operator);
10458         add_anchor_token(T_register);
10459         add_anchor_token(T_reinterpret_cast);
10460         add_anchor_token(T_restrict);
10461         add_anchor_token(T_return);
10462         add_anchor_token(T_short);
10463         add_anchor_token(T_signed);
10464         add_anchor_token(T_sizeof);
10465         add_anchor_token(T_static);
10466         add_anchor_token(T_static_cast);
10467         add_anchor_token(T_struct);
10468         add_anchor_token(T_switch);
10469         add_anchor_token(T_template);
10470         add_anchor_token(T_this);
10471         add_anchor_token(T_throw);
10472         add_anchor_token(T_true);
10473         add_anchor_token(T_try);
10474         add_anchor_token(T_typedef);
10475         add_anchor_token(T_typeid);
10476         add_anchor_token(T_typename);
10477         add_anchor_token(T_typeof);
10478         add_anchor_token(T_union);
10479         add_anchor_token(T_unsigned);
10480         add_anchor_token(T_using);
10481         add_anchor_token(T_void);
10482         add_anchor_token(T_volatile);
10483         add_anchor_token(T_wchar_t);
10484         add_anchor_token(T_while);
10485
10486         size_t const  top       = environment_top();
10487         scope_t      *old_scope = scope_push(&statement->compound.scope);
10488
10489         statement_t **anchor            = &statement->compound.statements;
10490         bool          only_decls_so_far = true;
10491         while (token.type != '}') {
10492                 if (token.type == T_EOF) {
10493                         errorf(&statement->base.source_position,
10494                                "EOF while parsing compound statement");
10495                         break;
10496                 }
10497                 statement_t *sub_statement = intern_parse_statement();
10498                 if (is_invalid_statement(sub_statement)) {
10499                         /* an error occurred. if we are at an anchor, return */
10500                         if (at_anchor())
10501                                 goto end_error;
10502                         continue;
10503                 }
10504
10505                 if (warning.declaration_after_statement) {
10506                         if (sub_statement->kind != STATEMENT_DECLARATION) {
10507                                 only_decls_so_far = false;
10508                         } else if (!only_decls_so_far) {
10509                                 warningf(&sub_statement->base.source_position,
10510                                          "ISO C90 forbids mixed declarations and code");
10511                         }
10512                 }
10513
10514                 *anchor = sub_statement;
10515
10516                 while (sub_statement->base.next != NULL)
10517                         sub_statement = sub_statement->base.next;
10518
10519                 anchor = &sub_statement->base.next;
10520         }
10521         next_token();
10522
10523         /* look over all statements again to produce no effect warnings */
10524         if (warning.unused_value) {
10525                 statement_t *sub_statement = statement->compound.statements;
10526                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10527                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10528                                 continue;
10529                         /* don't emit a warning for the last expression in an expression
10530                          * statement as it has always an effect */
10531                         if (inside_expression_statement && sub_statement->base.next == NULL)
10532                                 continue;
10533
10534                         expression_t *expression = sub_statement->expression.expression;
10535                         if (!expression_has_effect(expression)) {
10536                                 warningf(&expression->base.source_position,
10537                                          "statement has no effect");
10538                         }
10539                 }
10540         }
10541
10542 end_error:
10543         rem_anchor_token(T_while);
10544         rem_anchor_token(T_wchar_t);
10545         rem_anchor_token(T_volatile);
10546         rem_anchor_token(T_void);
10547         rem_anchor_token(T_using);
10548         rem_anchor_token(T_unsigned);
10549         rem_anchor_token(T_union);
10550         rem_anchor_token(T_typeof);
10551         rem_anchor_token(T_typename);
10552         rem_anchor_token(T_typeid);
10553         rem_anchor_token(T_typedef);
10554         rem_anchor_token(T_try);
10555         rem_anchor_token(T_true);
10556         rem_anchor_token(T_throw);
10557         rem_anchor_token(T_this);
10558         rem_anchor_token(T_template);
10559         rem_anchor_token(T_switch);
10560         rem_anchor_token(T_struct);
10561         rem_anchor_token(T_static_cast);
10562         rem_anchor_token(T_static);
10563         rem_anchor_token(T_sizeof);
10564         rem_anchor_token(T_signed);
10565         rem_anchor_token(T_short);
10566         rem_anchor_token(T_return);
10567         rem_anchor_token(T_restrict);
10568         rem_anchor_token(T_reinterpret_cast);
10569         rem_anchor_token(T_register);
10570         rem_anchor_token(T_operator);
10571         rem_anchor_token(T_new);
10572         rem_anchor_token(T_long);
10573         rem_anchor_token(T_int);
10574         rem_anchor_token(T_inline);
10575         rem_anchor_token(T_if);
10576         rem_anchor_token(T_goto);
10577         rem_anchor_token(T_for);
10578         rem_anchor_token(T_float);
10579         rem_anchor_token(T_false);
10580         rem_anchor_token(T_extern);
10581         rem_anchor_token(T_enum);
10582         rem_anchor_token(T_dynamic_cast);
10583         rem_anchor_token(T_do);
10584         rem_anchor_token(T_double);
10585         rem_anchor_token(T_delete);
10586         rem_anchor_token(T_default);
10587         rem_anchor_token(T_continue);
10588         rem_anchor_token(T_const_cast);
10589         rem_anchor_token(T_const);
10590         rem_anchor_token(T_class);
10591         rem_anchor_token(T_char);
10592         rem_anchor_token(T_case);
10593         rem_anchor_token(T_break);
10594         rem_anchor_token(T_bool);
10595         rem_anchor_token(T_auto);
10596         rem_anchor_token(T_asm);
10597         rem_anchor_token(T___thread);
10598         rem_anchor_token(T___real__);
10599         rem_anchor_token(T___label__);
10600         rem_anchor_token(T___imag__);
10601         rem_anchor_token(T___func__);
10602         rem_anchor_token(T___extension__);
10603         rem_anchor_token(T___builtin_va_start);
10604         rem_anchor_token(T___attribute__);
10605         rem_anchor_token(T___alignof__);
10606         rem_anchor_token(T___PRETTY_FUNCTION__);
10607         rem_anchor_token(T___FUNCTION__);
10608         rem_anchor_token(T__Imaginary);
10609         rem_anchor_token(T__Complex);
10610         rem_anchor_token(T__Bool);
10611         rem_anchor_token(T_WIDE_STRING_LITERAL);
10612         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10613         rem_anchor_token(T_STRING_LITERAL);
10614         rem_anchor_token(T_PLUSPLUS);
10615         rem_anchor_token(T_MINUSMINUS);
10616         rem_anchor_token(T_INTEGER);
10617         rem_anchor_token(T_IDENTIFIER);
10618         rem_anchor_token(T_FLOATINGPOINT);
10619         rem_anchor_token(T_COLONCOLON);
10620         rem_anchor_token(T_CHARACTER_CONSTANT);
10621         rem_anchor_token('~');
10622         rem_anchor_token('{');
10623         rem_anchor_token('-');
10624         rem_anchor_token('+');
10625         rem_anchor_token('*');
10626         rem_anchor_token('(');
10627         rem_anchor_token('&');
10628         rem_anchor_token('!');
10629         rem_anchor_token('}');
10630         assert(current_scope == &statement->compound.scope);
10631         scope_pop(old_scope);
10632         environment_pop_to(top);
10633
10634         POP_PARENT;
10635         return statement;
10636 }
10637
10638 /**
10639  * Check for unused global static functions and variables
10640  */
10641 static void check_unused_globals(void)
10642 {
10643         if (!warning.unused_function && !warning.unused_variable)
10644                 return;
10645
10646         for (const entity_t *entity = file_scope->entities; entity != NULL;
10647              entity = entity->base.next) {
10648                 if (!is_declaration(entity))
10649                         continue;
10650
10651                 const declaration_t *declaration = &entity->declaration;
10652                 if (declaration->used                  ||
10653                     declaration->modifiers & DM_UNUSED ||
10654                     declaration->modifiers & DM_USED   ||
10655                     declaration->storage_class != STORAGE_CLASS_STATIC)
10656                         continue;
10657
10658                 type_t *const type = declaration->type;
10659                 const char *s;
10660                 if (entity->kind == ENTITY_FUNCTION) {
10661                         /* inhibit warning for static inline functions */
10662                         if (entity->function.is_inline)
10663                                 continue;
10664
10665                         s = entity->function.statement != NULL ? "defined" : "declared";
10666                 } else {
10667                         s = "defined";
10668                 }
10669
10670                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
10671                         type, declaration->base.symbol, s);
10672         }
10673 }
10674
10675 static void parse_global_asm(void)
10676 {
10677         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10678
10679         eat(T_asm);
10680         expect('(', end_error);
10681
10682         statement->asms.asm_text = parse_string_literals();
10683         statement->base.next     = unit->global_asm;
10684         unit->global_asm         = statement;
10685
10686         expect(')', end_error);
10687         expect(';', end_error);
10688
10689 end_error:;
10690 }
10691
10692 static void parse_linkage_specification(void)
10693 {
10694         eat(T_extern);
10695
10696         const char *linkage = parse_string_literals().begin;
10697
10698         linkage_kind_t old_linkage = current_linkage;
10699         linkage_kind_t new_linkage;
10700         if (strcmp(linkage, "C") == 0) {
10701                 new_linkage = LINKAGE_C;
10702         } else if (strcmp(linkage, "C++") == 0) {
10703                 new_linkage = LINKAGE_CXX;
10704         } else {
10705                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
10706                 new_linkage = LINKAGE_INVALID;
10707         }
10708         current_linkage = new_linkage;
10709
10710         if (next_if('{')) {
10711                 parse_externals();
10712                 expect('}', end_error);
10713         } else {
10714                 parse_external();
10715         }
10716
10717 end_error:
10718         assert(current_linkage == new_linkage);
10719         current_linkage = old_linkage;
10720 }
10721
10722 static void parse_external(void)
10723 {
10724         switch (token.type) {
10725                 DECLARATION_START_NO_EXTERN
10726                 case T_IDENTIFIER:
10727                 case T___extension__:
10728                 /* tokens below are for implicit int */
10729                 case '&': /* & x; -> int& x; (and error later, because C++ has no
10730                              implicit int) */
10731                 case '*': /* * x; -> int* x; */
10732                 case '(': /* (x); -> int (x); */
10733                         parse_external_declaration();
10734                         return;
10735
10736                 case T_extern:
10737                         if (look_ahead(1)->type == T_STRING_LITERAL) {
10738                                 parse_linkage_specification();
10739                         } else {
10740                                 parse_external_declaration();
10741                         }
10742                         return;
10743
10744                 case T_asm:
10745                         parse_global_asm();
10746                         return;
10747
10748                 case T_namespace:
10749                         parse_namespace_definition();
10750                         return;
10751
10752                 case ';':
10753                         if (!strict_mode) {
10754                                 if (warning.other)
10755                                         warningf(HERE, "stray ';' outside of function");
10756                                 next_token();
10757                                 return;
10758                         }
10759                         /* FALLTHROUGH */
10760
10761                 default:
10762                         errorf(HERE, "stray %K outside of function", &token);
10763                         if (token.type == '(' || token.type == '{' || token.type == '[')
10764                                 eat_until_matching_token(token.type);
10765                         next_token();
10766                         return;
10767         }
10768 }
10769
10770 static void parse_externals(void)
10771 {
10772         add_anchor_token('}');
10773         add_anchor_token(T_EOF);
10774
10775 #ifndef NDEBUG
10776         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10777         unsigned char token_anchor_copy[T_LAST_TOKEN];
10778         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10779 #endif
10780
10781         while (token.type != T_EOF && token.type != '}') {
10782 #ifndef NDEBUG
10783                 bool anchor_leak = false;
10784                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10785                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
10786                         if (count != 0) {
10787                                 /* the anchor set and its copy differs */
10788                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
10789                                 anchor_leak = true;
10790                         }
10791                 }
10792                 if (in_gcc_extension) {
10793                         /* an gcc extension scope was not closed */
10794                         errorf(HERE, "Leaked __extension__");
10795                         anchor_leak = true;
10796                 }
10797
10798                 if (anchor_leak)
10799                         abort();
10800 #endif
10801
10802                 parse_external();
10803         }
10804
10805         rem_anchor_token(T_EOF);
10806         rem_anchor_token('}');
10807 }
10808
10809 /**
10810  * Parse a translation unit.
10811  */
10812 static void parse_translation_unit(void)
10813 {
10814         add_anchor_token(T_EOF);
10815
10816         while (true) {
10817                 parse_externals();
10818
10819                 if (token.type == T_EOF)
10820                         break;
10821
10822                 errorf(HERE, "stray %K outside of function", &token);
10823                 if (token.type == '(' || token.type == '{' || token.type == '[')
10824                         eat_until_matching_token(token.type);
10825                 next_token();
10826         }
10827 }
10828
10829 /**
10830  * Parse the input.
10831  *
10832  * @return  the translation unit or NULL if errors occurred.
10833  */
10834 void start_parsing(void)
10835 {
10836         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10837         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10838         diagnostic_count  = 0;
10839         error_count       = 0;
10840         warning_count     = 0;
10841
10842         print_to_file(stderr);
10843
10844         assert(unit == NULL);
10845         unit = allocate_ast_zero(sizeof(unit[0]));
10846
10847         assert(file_scope == NULL);
10848         file_scope = &unit->scope;
10849
10850         assert(current_scope == NULL);
10851         scope_push(&unit->scope);
10852
10853         create_gnu_builtins();
10854         if (c_mode & _MS)
10855                 create_microsoft_intrinsics();
10856 }
10857
10858 translation_unit_t *finish_parsing(void)
10859 {
10860         assert(current_scope == &unit->scope);
10861         scope_pop(NULL);
10862
10863         assert(file_scope == &unit->scope);
10864         check_unused_globals();
10865         file_scope = NULL;
10866
10867         DEL_ARR_F(environment_stack);
10868         DEL_ARR_F(label_stack);
10869
10870         translation_unit_t *result = unit;
10871         unit = NULL;
10872         return result;
10873 }
10874
10875 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10876  * are given length one. */
10877 static void complete_incomplete_arrays(void)
10878 {
10879         size_t n = ARR_LEN(incomplete_arrays);
10880         for (size_t i = 0; i != n; ++i) {
10881                 declaration_t *const decl      = incomplete_arrays[i];
10882                 type_t        *const orig_type = decl->type;
10883                 type_t        *const type      = skip_typeref(orig_type);
10884
10885                 if (!is_type_incomplete(type))
10886                         continue;
10887
10888                 if (warning.other) {
10889                         warningf(&decl->base.source_position,
10890                                         "array '%#T' assumed to have one element",
10891                                         orig_type, decl->base.symbol);
10892                 }
10893
10894                 type_t *const new_type = duplicate_type(type);
10895                 new_type->array.size_constant     = true;
10896                 new_type->array.has_implicit_size = true;
10897                 new_type->array.size              = 1;
10898
10899                 type_t *const result = identify_new_type(new_type);
10900
10901                 decl->type = result;
10902         }
10903 }
10904
10905 void prepare_main_collect2(entity_t *entity)
10906 {
10907         // create call to __main
10908         symbol_t *symbol         = symbol_table_insert("__main");
10909         entity_t *subsubmain_ent
10910                 = create_implicit_function(symbol, &builtin_source_position);
10911
10912         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10913         type_t       *ftype       = subsubmain_ent->declaration.type;
10914         ref->base.source_position = builtin_source_position;
10915         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10916         ref->reference.entity     = subsubmain_ent;
10917
10918         expression_t *call = allocate_expression_zero(EXPR_CALL);
10919         call->base.source_position = builtin_source_position;
10920         call->base.type            = type_void;
10921         call->call.function        = ref;
10922
10923         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10924         expr_statement->base.source_position  = builtin_source_position;
10925         expr_statement->expression.expression = call;
10926
10927         statement_t *statement = entity->function.statement;
10928         assert(statement->kind == STATEMENT_COMPOUND);
10929         compound_statement_t *compounds = &statement->compound;
10930
10931         expr_statement->base.next = compounds->statements;
10932         compounds->statements     = expr_statement;
10933 }
10934
10935 void parse(void)
10936 {
10937         lookahead_bufpos = 0;
10938         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10939                 next_token();
10940         }
10941         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10942         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10943         parse_translation_unit();
10944         complete_incomplete_arrays();
10945         DEL_ARR_F(incomplete_arrays);
10946         incomplete_arrays = NULL;
10947 }
10948
10949 /**
10950  * Initialize the parser.
10951  */
10952 void init_parser(void)
10953 {
10954         sym_anonymous = symbol_table_insert("<anonymous>");
10955
10956         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10957
10958         init_expression_parsers();
10959         obstack_init(&temp_obst);
10960 }
10961
10962 /**
10963  * Terminate the parser.
10964  */
10965 void exit_parser(void)
10966 {
10967         obstack_free(&temp_obst, NULL);
10968 }